diff --git a/group_vars/matrix_servers b/group_vars/matrix_servers
index f5eb1cb8..904b2291 100755
--- a/group_vars/matrix_servers
+++ b/group_vars/matrix_servers
@@ -47,12 +47,19 @@ matrix_appservice_discord_systemd_required_services_list: |
     ['docker.service']
     +
     (['matrix-synapse.service'] if matrix_synapse_enabled else [])
+    +
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
   }}
 
 matrix_appservice_discord_appservice_token: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'discord.as.token') | to_uuid }}"
 
 matrix_appservice_discord_homeserver_token: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'discord.hs.token') | to_uuid }}"
 
+# We only make this use Postgres if our own Postgres server is enabled.
+# It's only then (for now) that we can automatically create the necessary database and user for this service.
+matrix_appservice_discord_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_appservice_discord_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'as.discord.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-bridge-appservice-discord
@@ -121,6 +128,10 @@ matrix_appservice_slack_systemd_required_services_list: |
     (['matrix-synapse.service'] if matrix_synapse_enabled else [])
   }}
 
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_appservice_slack_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_appservice_slack_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'as.slack.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-bridge-appservice-slack
@@ -156,6 +167,10 @@ matrix_appservice_irc_appservice_token: "{{ matrix_synapse_macaroon_secret_key |
 
 matrix_appservice_irc_homeserver_token: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'irc.hs.token') | to_uuid }}"
 
+matrix_appservice_irc_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'nedb' }}"
+matrix_appservice_irc_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'as.irc.db') | to_uuid }}"
+
+
 ######################################################################
 #
 # /matrix-bridge-appservice-irc
@@ -179,6 +194,8 @@ matrix_mautrix_facebook_systemd_required_services_list: |
     ['docker.service']
     +
     (['matrix-synapse.service'] if matrix_synapse_enabled else [])
+    +
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
   }}
 
 matrix_mautrix_facebook_appservice_token: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'fb.as.token') | to_uuid }}"
@@ -189,6 +206,10 @@ matrix_mautrix_facebook_login_shared_secret: "{{ matrix_synapse_ext_password_pro
 
 matrix_mautrix_facebook_bridge_presence: "{{ matrix_synapse_use_presence if matrix_synapse_enabled else true }}"
 
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_mautrix_facebook_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_mautrix_facebook_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'as.mautrix_facebook.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-bridge-mautrix-facebook
@@ -212,6 +233,8 @@ matrix_mautrix_hangouts_systemd_required_services_list: |
     ['docker.service']
     +
     (['matrix-synapse.service'] if matrix_synapse_enabled else [])
+    +
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
   }}
 
 matrix_mautrix_hangouts_appservice_token: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'ho.as.token') | to_uuid }}"
@@ -222,6 +245,10 @@ matrix_mautrix_hangouts_container_http_host_bind_port: "{{ '' if matrix_nginx_pr
 
 matrix_mautrix_hangouts_login_shared_secret: "{{ matrix_synapse_ext_password_provider_shared_secret_auth_shared_secret if matrix_synapse_ext_password_provider_shared_secret_auth_enabled else '' }}"
 
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_mautrix_hangouts_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_mautrix_hangouts_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'as.mautrix_hangouts.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-bridge-mautrix-hangouts
@@ -246,6 +273,8 @@ matrix_mautrix_telegram_systemd_required_services_list: |
     ['docker.service']
     +
     (['matrix-synapse.service'] if matrix_synapse_enabled else [])
+    +
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
   }}
 
 matrix_mautrix_telegram_appservice_token: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'telegr.as.token') | to_uuid }}"
@@ -258,6 +287,10 @@ matrix_mautrix_telegram_container_http_host_bind_port: "{{ '' if matrix_nginx_pr
 
 matrix_mautrix_telegram_login_shared_secret: "{{ matrix_synapse_ext_password_provider_shared_secret_auth_shared_secret if matrix_synapse_ext_password_provider_shared_secret_auth_enabled else '' }}"
 
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_mautrix_telegram_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_mautrix_telegram_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'as.mautrix_telegram.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-bridge-mautrix-telegram
@@ -278,6 +311,8 @@ matrix_mautrix_whatsapp_systemd_required_services_list: |
     ['docker.service']
     +
     (['matrix-synapse.service'] if matrix_synapse_enabled else [])
+    +
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
   }}
 
 matrix_mautrix_whatsapp_appservice_token: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'whats.as.token') | to_uuid }}"
@@ -286,6 +321,10 @@ matrix_mautrix_whatsapp_homeserver_token: "{{ matrix_synapse_macaroon_secret_key
 
 matrix_mautrix_whatsapp_login_shared_secret: "{{ matrix_synapse_ext_password_provider_shared_secret_auth_shared_secret if matrix_synapse_ext_password_provider_shared_secret_auth_enabled else '' }}"
 
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_mautrix_whatsapp_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_mautrix_whatsapp_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'as.mautrix_whatsapp.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-bridge-mautrix-whatsapp
@@ -334,6 +373,8 @@ matrix_mx_puppet_skype_systemd_required_services_list: |
     ['docker.service']
     +
     (['matrix-synapse.service'] if matrix_synapse_enabled else [])
+    +
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
   }}
 
 matrix_mx_puppet_skype_appservice_token: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'skype.as.tok') | to_uuid }}"
@@ -342,6 +383,10 @@ matrix_mx_puppet_skype_homeserver_token: "{{ matrix_synapse_macaroon_secret_key
 
 matrix_mx_puppet_skype_login_shared_secret: "{{ matrix_synapse_ext_password_provider_shared_secret_auth_shared_secret if matrix_synapse_ext_password_provider_shared_secret_auth_enabled else '' }}"
 
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_mx_puppet_skype_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_mx_puppet_skype_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'as.mx_puppet_skype.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-bridge-mx-puppet-skype
@@ -365,6 +410,8 @@ matrix_mx_puppet_slack_systemd_required_services_list: |
     ['docker.service']
     +
     (['matrix-synapse.service'] if matrix_synapse_enabled else [])
+    +
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
   }}
 
 matrix_mx_puppet_slack_appservice_token: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'mxslk.as.tok') | to_uuid }}"
@@ -373,6 +420,10 @@ matrix_mx_puppet_slack_homeserver_token: "{{ matrix_synapse_macaroon_secret_key
 
 matrix_mx_puppet_slack_login_shared_secret: "{{ matrix_synapse_ext_password_provider_shared_secret_auth_shared_secret if matrix_synapse_ext_password_provider_shared_secret_auth_enabled else '' }}"
 
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_mx_puppet_slack_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_mx_puppet_slack_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'as.mx_puppet_slack.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-bridge-mx-puppet-slack
@@ -395,6 +446,8 @@ matrix_mx_puppet_twitter_systemd_required_services_list: |
     ['docker.service']
     +
     (['matrix-synapse.service'] if matrix_synapse_enabled else [])
+    +
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
   }}
 
 matrix_mx_puppet_twitter_appservice_token: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'mxtwt.as.tok') | to_uuid }}"
@@ -405,6 +458,10 @@ matrix_mx_puppet_twitter_login_shared_secret: "{{ matrix_synapse_ext_password_pr
 
 matrix_mx_puppet_twitter_container_http_host_bind_port: "{{ '' if matrix_nginx_proxy_enabled else ('127.0.0.1:' ~ matrix_mx_puppet_twitter_appservice_port) }}"
 
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_mx_puppet_twitter_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_mx_puppet_twitter_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'as.mx_puppet_twitter.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-bridge-mx-puppet-twitter
@@ -428,6 +485,8 @@ matrix_mx_puppet_instagram_systemd_required_services_list: |
     ['docker.service']
     +
     (['matrix-synapse.service'] if matrix_synapse_enabled else [])
+    +
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
   }}
 
 matrix_mx_puppet_instagram_appservice_token: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'mxig.as.tok') | to_uuid }}"
@@ -436,6 +495,10 @@ matrix_mx_puppet_instagram_homeserver_token: "{{ matrix_synapse_macaroon_secret_
 
 matrix_mx_puppet_instagram_login_shared_secret: "{{ matrix_synapse_ext_password_provider_shared_secret_auth_shared_secret if matrix_synapse_ext_password_provider_shared_secret_auth_enabled else '' }}"
 
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_mx_puppet_instagram_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_mx_puppet_instagram_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'as.mx_puppet_instagram.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-bridge-mx-puppet-instagram
@@ -458,6 +521,8 @@ matrix_mx_puppet_discord_systemd_required_services_list: |
     ['docker.service']
     +
     (['matrix-synapse.service'] if matrix_synapse_enabled else [])
+    +
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
   }}
 
 matrix_mx_puppet_discord_appservice_token: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'mxdsc.as.tok') | to_uuid }}"
@@ -466,6 +531,10 @@ matrix_mx_puppet_discord_homeserver_token: "{{ matrix_synapse_macaroon_secret_ke
 
 matrix_mx_puppet_discord_login_shared_secret: "{{ matrix_synapse_ext_password_provider_shared_secret_auth_shared_secret if matrix_synapse_ext_password_provider_shared_secret_auth_enabled else '' }}"
 
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_mx_puppet_discord_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_mx_puppet_discord_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'as.mx_puppet_discord.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-bridge-mx-puppet-discord
@@ -488,6 +557,8 @@ matrix_mx_puppet_steam_systemd_required_services_list: |
     ['docker.service']
     +
     (['matrix-synapse.service'] if matrix_synapse_enabled else [])
+    +
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
   }}
 
 matrix_mx_puppet_steam_appservice_token: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'mxste.as.tok') | to_uuid }}"
@@ -496,6 +567,10 @@ matrix_mx_puppet_steam_homeserver_token: "{{ matrix_synapse_macaroon_secret_key
 
 matrix_mx_puppet_steam_login_shared_secret: "{{ matrix_synapse_ext_password_provider_shared_secret_auth_shared_secret if matrix_synapse_ext_password_provider_shared_secret_auth_enabled else '' }}"
 
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_mx_puppet_steam_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_mx_puppet_steam_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'as.mx_puppet_steam.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-bridge-mx-puppet-steam
@@ -512,6 +587,17 @@ matrix_mx_puppet_steam_login_shared_secret: "{{ matrix_synapse_ext_password_prov
 # We don't enable bots by default.
 matrix_bot_matrix_reminder_bot_enabled: false
 
+matrix_bot_matrix_reminder_bot_systemd_required_services_list: |
+  {{
+    ['docker.service']
+    +
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
+  }}
+
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_bot_matrix_reminder_bot_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_bot_matrix_reminder_bot_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'reminder.bot.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-bot-matrix-reminder-bot
@@ -606,6 +692,17 @@ matrix_dimension_container_http_host_bind_port: "{{ '' if matrix_nginx_proxy_ena
 matrix_integration_manager_rest_url: "{{ matrix_dimension_integrations_rest_url if matrix_dimension_enabled else None }}"
 matrix_integration_manager_ui_url: "{{ matrix_dimension_integrations_ui_url if matrix_dimension_enabled else None }}"
 
+matrix_dimension_systemd_required_services_list: |
+  {{
+    ['docker.service']
+    +
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
+  }}
+
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_dimension_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_dimension_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'dimension.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-dimension
@@ -750,6 +847,11 @@ matrix_ma1sd_threepid_medium_email_connectors_smtp_tls: 0
 
 matrix_ma1sd_self_check_validate_certificates: "{{ false if matrix_ssl_retrieval_method == 'self-signed' else true }}"
 
+matrix_ma1sd_systemd_required_services_list: |
+  {{
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
+  }}
+
 matrix_ma1sd_systemd_wanted_services_list: |
   {{
     (['matrix-corporal.service'] if matrix_corporal_enabled else ['matrix-synapse.service'])
@@ -759,6 +861,10 @@ matrix_ma1sd_systemd_wanted_services_list: |
     (['matrix-mailer.service'] if matrix_mailer_enabled else [])
   }}
 
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_ma1sd_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_ma1sd_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'ma1sd.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-ma1sd
@@ -875,6 +981,133 @@ matrix_postgres_connection_username: "synapse"
 matrix_postgres_connection_password: "synapse-password"
 matrix_postgres_db_name: "homeserver"
 
+matrix_postgres_pgloader_container_image_self_build: "{{ matrix_architecture != 'amd64' }}"
+
+matrix_postgres_additional_databases: |
+  {{
+    ([{
+      'name': matrix_ma1sd_database_name,
+      'username': matrix_ma1sd_database_username,
+      'password': matrix_ma1sd_database_password,
+    }] if (matrix_ma1sd_enabled and matrix_ma1sd_database_engine == 'postgres' and matrix_ma1sd_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_bot_matrix_reminder_bot_database_name,
+      'username': matrix_bot_matrix_reminder_bot_database_username,
+      'password': matrix_bot_matrix_reminder_bot_database_password,
+    }] if (matrix_bot_matrix_reminder_bot_enabled and matrix_bot_matrix_reminder_bot_database_engine == 'postgres' and matrix_bot_matrix_reminder_bot_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_registration_database_name,
+      'username': matrix_registration_database_username,
+      'password': matrix_registration_database_password,
+    }] if (matrix_registration_enabled and matrix_registration_database_engine == 'postgres' and matrix_registration_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_appservice_discord_database_name,
+      'username': matrix_appservice_discord_database_username,
+      'password': matrix_appservice_discord_database_password,
+    }] if (matrix_appservice_discord_enabled and matrix_appservice_discord_database_engine == 'postgres' and matrix_appservice_discord_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_appservice_slack_database_name,
+      'username': matrix_appservice_slack_database_username,
+      'password': matrix_appservice_slack_database_password,
+    }] if (matrix_appservice_slack_enabled and matrix_appservice_slack_database_engine == 'postgres' and matrix_appservice_slack_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_appservice_irc_database_name,
+      'username': matrix_appservice_irc_database_username,
+      'password': matrix_appservice_irc_database_password,
+    }] if (matrix_appservice_irc_enabled and matrix_appservice_irc_database_engine == 'postgres' and matrix_appservice_irc_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_mautrix_facebook_database_name,
+      'username': matrix_mautrix_facebook_database_username,
+      'password': matrix_mautrix_facebook_database_password,
+    }] if (matrix_mautrix_facebook_enabled and matrix_mautrix_facebook_database_engine == 'postgres' and matrix_mautrix_facebook_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_mautrix_hangouts_database_name,
+      'username': matrix_mautrix_hangouts_database_username,
+      'password': matrix_mautrix_hangouts_database_password,
+    }] if (matrix_mautrix_hangouts_enabled and matrix_mautrix_hangouts_database_engine == 'postgres' and matrix_mautrix_hangouts_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_mautrix_telegram_database_name,
+      'username': matrix_mautrix_telegram_database_username,
+      'password': matrix_mautrix_telegram_database_password,
+    }] if (matrix_mautrix_telegram_enabled and matrix_mautrix_telegram_database_engine == 'postgres' and matrix_mautrix_telegram_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_mautrix_whatsapp_database_name,
+      'username': matrix_mautrix_whatsapp_database_username,
+      'password': matrix_mautrix_whatsapp_database_password,
+    }] if (matrix_mautrix_whatsapp_enabled and matrix_mautrix_whatsapp_database_engine == 'postgres' and matrix_mautrix_whatsapp_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': 'matrix_bridge_sms',
+      'username': 'matrix_bridge_sms',
+      'password': matrix_synapse_macaroon_secret_key | password_hash('sha512', 'bridge_sms.db.secret') | to_uuid,
+    }] if matrix_sms_bridge_enabled else [])
+    +
+    ([{
+      'name': matrix_mx_puppet_skype_database_name,
+      'username': matrix_mx_puppet_skype_database_username,
+      'password': matrix_mx_puppet_skype_database_password,
+    }] if (matrix_mx_puppet_skype_enabled and matrix_mx_puppet_skype_database_engine == 'postgres' and matrix_mx_puppet_skype_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_mx_puppet_slack_database_name,
+      'username': matrix_mx_puppet_slack_database_username,
+      'password': matrix_mx_puppet_slack_database_password,
+    }] if (matrix_mx_puppet_slack_enabled and matrix_mx_puppet_slack_database_engine == 'postgres' and matrix_mx_puppet_slack_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_mx_puppet_twitter_database_name,
+      'username': matrix_mx_puppet_twitter_database_username,
+      'password': matrix_mx_puppet_twitter_database_password,
+    }] if (matrix_mx_puppet_twitter_enabled and matrix_mx_puppet_twitter_database_engine == 'postgres' and matrix_mx_puppet_twitter_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_mx_puppet_instagram_database_name,
+      'username': matrix_mx_puppet_instagram_database_username,
+      'password': matrix_mx_puppet_instagram_database_password,
+    }] if (matrix_mx_puppet_instagram_enabled and matrix_mx_puppet_instagram_database_engine == 'postgres' and matrix_mx_puppet_instagram_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_mx_puppet_discord_database_name,
+      'username': matrix_mx_puppet_discord_database_username,
+      'password': matrix_mx_puppet_discord_database_password,
+    }] if (matrix_mx_puppet_discord_enabled  and matrix_mx_puppet_discord_database_engine == 'postgres' and matrix_mx_puppet_discord_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_mx_puppet_steam_database_name,
+      'username': matrix_mx_puppet_steam_database_username,
+      'password': matrix_mx_puppet_steam_database_password,
+    }] if (matrix_mx_puppet_steam_enabled and matrix_mx_puppet_steam_database_engine == 'postgres' and matrix_mx_puppet_steam_database_hostname == 'matrix-postgres') else [])
+    +
+    ([{
+      'name': matrix_dimension_database_name,
+      'username': matrix_dimension_database_username,
+      'password': matrix_dimension_database_password,
+    }] if (matrix_dimension_enabled and matrix_dimension_database_engine == 'postgres' and matrix_dimension_database_hostname == 'matrix-postgres') else [])
+   }}
+
+matrix_postgres_import_roles_to_ignore: |
+  {{
+    [matrix_postgres_connection_username]
+    +
+    matrix_postgres_additional_databases|map(attribute='username')
+  }}
+
+matrix_postgres_import_databases_to_ignore: |
+  {{
+    [matrix_postgres_db_name]
+    +
+    matrix_postgres_additional_databases|map(attribute='name')
+  }}
+
 ######################################################################
 #
 # /matrix-postgres
@@ -1071,6 +1304,17 @@ matrix_registration_api_validate_certs: "{{ false if matrix_ssl_retrieval_method
 
 matrix_registration_container_image_self_build: "{{ matrix_architecture != 'amd64' }}"
 
+matrix_registration_systemd_required_services_list: |
+  {{
+    ['docker.service']
+    +
+    (['matrix-postgres.service'] if matrix_postgres_enabled else [])
+  }}
+
+# Postgres is the default, except if not using `matrix_postgres` (internal postgres)
+matrix_registration_database_engine: "{{ 'postgres' if matrix_postgres_enabled else 'sqlite' }}"
+matrix_registration_database_password: "{{ matrix_synapse_macaroon_secret_key | password_hash('sha512', 'mx.registr.db') | to_uuid }}"
+
 ######################################################################
 #
 # /matrix-registration
diff --git a/roles/matrix-bot-matrix-reminder-bot/defaults/main.yml b/roles/matrix-bot-matrix-reminder-bot/defaults/main.yml
index 33028147..29bc8307 100644
--- a/roles/matrix-bot-matrix-reminder-bot/defaults/main.yml
+++ b/roles/matrix-bot-matrix-reminder-bot/defaults/main.yml
@@ -21,6 +21,34 @@ matrix_bot_matrix_reminder_bot_systemd_required_services_list: ['docker.service'
 matrix_bot_matrix_reminder_bot_systemd_wanted_services_list: []
 
 
+# Database-related configuration fields.
+#
+# To use SQLite, stick to these defaults.
+#
+# To use Postgres:
+# - change the engine (`matrix_bot_matrix_reminder_bot_database_engine: 'postgres'`)
+# - adjust your database credentials via the `matrix_bot_matrix_reminder_bot_database_*` variables
+matrix_bot_matrix_reminder_bot_database_engine: 'sqlite'
+
+matrix_bot_matrix_reminder_bot_sqlite_database_path_local: "{{ matrix_bot_matrix_reminder_bot_data_path }}/bot.db"
+matrix_bot_matrix_reminder_bot_sqlite_database_path_in_container: "/data/bot.db"
+
+matrix_bot_matrix_reminder_bot_database_username: 'matrix_reminder_bot'
+matrix_bot_matrix_reminder_bot_database_password: 'some-password'
+matrix_bot_matrix_reminder_bot_database_hostname: 'matrix-postgres'
+matrix_bot_matrix_reminder_bot_database_port: 5432
+matrix_bot_matrix_reminder_bot_database_name: 'matrix_reminder_bot'
+
+matrix_bot_matrix_reminder_bot_database_connection_string: 'postgres://{{ matrix_bot_matrix_reminder_bot_database_username }}:{{ matrix_bot_matrix_reminder_bot_database_password }}@{{ matrix_bot_matrix_reminder_bot_database_hostname }}:{{ matrix_bot_matrix_reminder_bot_database_port }}/{{ matrix_bot_matrix_reminder_bot_database_name }}'
+
+matrix_bot_matrix_reminder_bot_storage_database: "{{
+	{
+		'sqlite': ('sqlite://' + matrix_bot_matrix_reminder_bot_sqlite_database_path_in_container),
+		'postgres': matrix_bot_matrix_reminder_bot_database_connection_string,
+	}[matrix_bot_matrix_reminder_bot_database_engine]
+}}"
+
+
 # The bot's username. This user needs to be created manually beforehand.
 # Also see `matrix_bot_matrix_reminder_bot_user_password`.
 matrix_bot_matrix_reminder_bot_matrix_user_id_localpart: "bot.matrix-reminder-bot"
diff --git a/roles/matrix-bot-matrix-reminder-bot/tasks/main.yml b/roles/matrix-bot-matrix-reminder-bot/tasks/main.yml
index ade3d191..fc2afddb 100644
--- a/roles/matrix-bot-matrix-reminder-bot/tasks/main.yml
+++ b/roles/matrix-bot-matrix-reminder-bot/tasks/main.yml
@@ -8,7 +8,14 @@
     - setup-all
     - setup-bot-matrix-reminder-bot
 
-- import_tasks: "{{ role_path }}/tasks/setup.yml"
+- import_tasks: "{{ role_path }}/tasks/setup_install.yml"
+  when: "run_setup|bool and matrix_bot_matrix_reminder_bot_enabled|bool"
+  tags:
+    - setup-all
+    - setup-bot-matrix-reminder-bot
+
+- import_tasks: "{{ role_path }}/tasks/setup_uninstall.yml"
+  when: "run_setup|bool and not matrix_bot_matrix_reminder_bot_enabled|bool"
   tags:
     - setup-all
     - setup-bot-matrix-reminder-bot
diff --git a/roles/matrix-bot-matrix-reminder-bot/tasks/setup.yml b/roles/matrix-bot-matrix-reminder-bot/tasks/setup.yml
deleted file mode 100644
index bc211e31..00000000
--- a/roles/matrix-bot-matrix-reminder-bot/tasks/setup.yml
+++ /dev/null
@@ -1,88 +0,0 @@
----
-
-#
-# Tasks related to setting up matrix-reminder-bot
-#
-
-- name: Ensure matrix-reminder-bot paths exist
-  file:
-    path: "{{ item.path }}"
-    state: directory
-    mode: 0750
-    owner: "{{ matrix_user_username }}"
-    group: "{{ matrix_user_groupname }}"
-  with_items:
-    - { path: "{{ matrix_bot_matrix_reminder_bot_config_path }}", when: true }
-    - { path: "{{ matrix_bot_matrix_reminder_bot_data_path }}", when: true }
-    - { path: "{{ matrix_bot_matrix_reminder_bot_data_store_path }}", when: true }
-  when: matrix_bot_matrix_reminder_bot_enabled|bool and item.when
-
-- name: Ensure matrix-reminder-bot image is pulled
-  docker_image:
-    name: "{{ matrix_bot_matrix_reminder_bot_docker_image }}"
-    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
-    force_source: "{{ matrix_bot_matrix_reminder_bot_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
-    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_bot_matrix_reminder_bot_docker_image_force_pull }}"
-  when: matrix_bot_matrix_reminder_bot_enabled|bool
-
-- name: Ensure matrix-reminder-bot config installed
-  copy:
-    content: "{{ matrix_bot_matrix_reminder_bot_configuration|to_nice_yaml }}"
-    dest: "{{ matrix_bot_matrix_reminder_bot_config_path }}/config.yaml"
-    mode: 0644
-    owner: "{{ matrix_user_username }}"
-    group: "{{ matrix_user_groupname }}"
-  when: matrix_bot_matrix_reminder_bot_enabled|bool
-
-- name: Ensure matrix-matrix-reminder-bot.service installed
-  template:
-    src: "{{ role_path }}/templates/systemd/matrix-bot-matrix-reminder-bot.service.j2"
-    dest: "{{ matrix_systemd_path }}/matrix-bot-matrix-reminder-bot.service"
-    mode: 0644
-  register: matrix_bot_matrix_reminder_bot_systemd_service_result
-  when: matrix_bot_matrix_reminder_bot_enabled|bool
-
-- name: Ensure systemd reloaded after matrix-matrix-reminder-bot.service installation
-  service:
-    daemon_reload: yes
-  when: "matrix_bot_matrix_reminder_bot_enabled|bool and matrix_bot_matrix_reminder_bot_systemd_service_result.changed"
-
-#
-# Tasks related to getting rid of matrix-reminder-bot (if it was previously enabled)
-#
-
-- name: Check existence of matrix-matrix-reminder-bot service
-  stat:
-    path: "{{ matrix_systemd_path }}/matrix-matrix-reminder-bot.service"
-  register: matrix_bot_matrix_reminder_bot_service_stat
-
-- name: Ensure matrix-matrix-reminder-bot is stopped
-  service:
-    name: matrix-matrix-reminder-bot
-    state: stopped
-    daemon_reload: yes
-  register: stopping_result
-  when: "not matrix_bot_matrix_reminder_bot_enabled|bool and matrix_bot_matrix_reminder_bot_service_stat.stat.exists"
-
-- name: Ensure matrix-matrix-reminder-bot.service doesn't exist
-  file:
-    path: "{{ matrix_systemd_path }}/matrix-matrix-reminder-bot.service"
-    state: absent
-  when: "not matrix_bot_matrix_reminder_bot_enabled|bool and matrix_bot_matrix_reminder_bot_service_stat.stat.exists"
-
-- name: Ensure systemd reloaded after matrix-matrix-reminder-bot.service removal
-  service:
-    daemon_reload: yes
-  when: "not matrix_bot_matrix_reminder_bot_enabled|bool and matrix_bot_matrix_reminder_bot_service_stat.stat.exists"
-
-- name: Ensure Matrix matrix-reminder-bot paths don't exist
-  file:
-    path: "{{ matrix_bot_matrix_reminder_bot_base_path }}"
-    state: absent
-  when: "not matrix_bot_matrix_reminder_bot_enabled|bool"
-
-- name: Ensure matrix-reminder-bot Docker image doesn't exist
-  docker_image:
-    name: "{{ matrix_bot_matrix_reminder_bot_docker_image }}"
-    state: absent
-  when: "not matrix_bot_matrix_reminder_bot_enabled|bool"
diff --git a/roles/matrix-bot-matrix-reminder-bot/tasks/setup_install.yml b/roles/matrix-bot-matrix-reminder-bot/tasks/setup_install.yml
new file mode 100644
index 00000000..fea1e00d
--- /dev/null
+++ b/roles/matrix-bot-matrix-reminder-bot/tasks/setup_install.yml
@@ -0,0 +1,73 @@
+---
+
+- set_fact:
+    matrix_bot_matrix_reminder_bot_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_bot_matrix_reminder_bot_sqlite_database_path_local }}"
+      register: matrix_bot_matrix_reminder_bot_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_bot_matrix_reminder_bot_sqlite_database_path_local }}"
+              dst: "{{ matrix_bot_matrix_reminder_bot_database_connection_string }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_bot_matrix_reminder_bot_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-bot-matrix-reminder-bot.service']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_bot_matrix_reminder_bot_requires_restart: true
+      when: "matrix_bot_matrix_reminder_bot_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_bot_matrix_reminder_bot_database_engine == 'postgres'"
+
+- name: Ensure matrix-reminder-bot paths exist
+  file:
+    path: "{{ item.path }}"
+    state: directory
+    mode: 0750
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+  with_items:
+    - { path: "{{ matrix_bot_matrix_reminder_bot_config_path }}", when: true }
+    - { path: "{{ matrix_bot_matrix_reminder_bot_data_path }}", when: true }
+    - { path: "{{ matrix_bot_matrix_reminder_bot_data_store_path }}", when: true }
+  when: "item.when|bool"
+
+- name: Ensure matrix-reminder-bot image is pulled
+  docker_image:
+    name: "{{ matrix_bot_matrix_reminder_bot_docker_image }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_bot_matrix_reminder_bot_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
+    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_bot_matrix_reminder_bot_docker_image_force_pull }}"
+
+- name: Ensure matrix-reminder-bot config installed
+  copy:
+    content: "{{ matrix_bot_matrix_reminder_bot_configuration|to_nice_yaml }}"
+    dest: "{{ matrix_bot_matrix_reminder_bot_config_path }}/config.yaml"
+    mode: 0644
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_user_groupname }}"
+
+- name: Ensure matrix-bot-matrix-reminder-bot.service installed
+  template:
+    src: "{{ role_path }}/templates/systemd/matrix-bot-matrix-reminder-bot.service.j2"
+    dest: "{{ matrix_systemd_path }}/matrix-bot-matrix-reminder-bot.service"
+    mode: 0644
+  register: matrix_bot_matrix_reminder_bot_systemd_service_result
+
+- name: Ensure systemd reloaded after matrix-bot-matrix-reminder-bot.service installation
+  service:
+    daemon_reload: yes
+  when: "matrix_bot_matrix_reminder_bot_systemd_service_result.changed|bool"
+
+- name: Ensure matrix-bot-matrix-reminder-bot.service restarted, if necessary
+  service:
+    name: "matrix-bot-matrix-reminder-bot.service"
+    state: restarted
+  when: "matrix_bot_matrix_reminder_bot_requires_restart|bool"
diff --git a/roles/matrix-bot-matrix-reminder-bot/tasks/setup_uninstall.yml b/roles/matrix-bot-matrix-reminder-bot/tasks/setup_uninstall.yml
new file mode 100644
index 00000000..744f474d
--- /dev/null
+++ b/roles/matrix-bot-matrix-reminder-bot/tasks/setup_uninstall.yml
@@ -0,0 +1,35 @@
+---
+
+- name: Check existence of matrix-matrix-reminder-bot service
+  stat:
+    path: "{{ matrix_systemd_path }}/matrix-bot-matrix-reminder-bot.service"
+  register: matrix_bot_matrix_reminder_bot_service_stat
+
+- name: Ensure matrix-matrix-reminder-bot is stopped
+  service:
+    name: matrix-matrix-reminder-bot
+    state: stopped
+    daemon_reload: yes
+  register: stopping_result
+  when: "matrix_bot_matrix_reminder_bot_service_stat.stat.exists|bool"
+
+- name: Ensure matrix-bot-matrix-reminder-bot.service doesn't exist
+  file:
+    path: "{{ matrix_systemd_path }}/matrix-bot-matrix-reminder-bot.service"
+    state: absent
+  when: "matrix_bot_matrix_reminder_bot_service_stat.stat.exists|bool"
+
+- name: Ensure systemd reloaded after matrix-bot-matrix-reminder-bot.service removal
+  service:
+    daemon_reload: yes
+  when: "matrix_bot_matrix_reminder_bot_service_stat.stat.exists|bool"
+
+- name: Ensure Matrix matrix-reminder-bot paths don't exist
+  file:
+    path: "{{ matrix_bot_matrix_reminder_bot_base_path }}"
+    state: absent
+
+- name: Ensure matrix-reminder-bot Docker image doesn't exist
+  docker_image:
+    name: "{{ matrix_bot_matrix_reminder_bot_docker_image }}"
+    state: absent
diff --git a/roles/matrix-bot-matrix-reminder-bot/templates/config.yaml.j2 b/roles/matrix-bot-matrix-reminder-bot/templates/config.yaml.j2
index e5ba5651..59643958 100644
--- a/roles/matrix-bot-matrix-reminder-bot/templates/config.yaml.j2
+++ b/roles/matrix-bot-matrix-reminder-bot/templates/config.yaml.j2
@@ -23,7 +23,7 @@ storage:
   # For Postgres, this would look like:
   #     database: "postgres://username:password@localhost/dbname?sslmode=disable"
   #database: "postgres://matrix-reminder-bot:remindme@localhost/matrix-reminder-bot?sslmode=disable"
-  database: "sqlite:///data/bot.db"
+  database: {{ matrix_bot_matrix_reminder_bot_storage_database|to_json }}
   # The path to a directory for internal bot storage
   # containing encryption keys, sync tokens, etc.
   store_path: "/data/store"
diff --git a/roles/matrix-bridge-appservice-discord/defaults/main.yml b/roles/matrix-bridge-appservice-discord/defaults/main.yml
index 9ca06b05..c7cdddb6 100644
--- a/roles/matrix-bridge-appservice-discord/defaults/main.yml
+++ b/roles/matrix-bridge-appservice-discord/defaults/main.yml
@@ -41,6 +41,30 @@ matrix_appservice_discord_bridge_homeserverUrl: "{{ matrix_homeserver_url }}"
 matrix_appservice_discord_bridge_disablePresence: false
 matrix_appservice_discord_bridge_enableSelfServiceBridging: false
 
+# Database-related configuration fields.
+#
+# To use SQLite, stick to these defaults.
+#
+# To use Postgres:
+# - change the engine (`matrix_appservice_discord_database_engine: 'postgres'`)
+# - adjust your database credentials via the `matrix_appservice_discord_postgres_*` variables
+matrix_appservice_discord_database_engine: 'sqlite'
+
+matrix_appservice_discord_sqlite_database_path_local: "{{ matrix_appservice_discord_data_path }}/discord.db"
+matrix_appservice_discord_sqlite_database_path_in_container: "/data/discord.db"
+
+matrix_appservice_discord_database_username: 'matrix_appservice_discord'
+matrix_appservice_discord_database_password: 'some-password'
+matrix_appservice_discord_database_hostname: 'matrix-postgres'
+matrix_appservice_discord_database_port: 5432
+matrix_appservice_discord_database_name: 'matrix_appservice_discord'
+
+# These 2 variables are what actually ends up in the bridge configuration.
+# It's best if you don't change them directly, but rather redefine the sub-variables that constitute them.
+matrix_appservice_discord_database_filename: "{{ matrix_appservice_discord_sqlite_database_path_in_container }}"
+matrix_appservice_discord_database_connString: 'postgresql://{{ matrix_appservice_discord_database_username }}:{{ matrix_appservice_discord_database_password }}@{{ matrix_appservice_discord_database_hostname }}:{{ matrix_appservice_discord_database_port }}/{{ matrix_appservice_discord_database_name }}'
+
+
 # Tells whether the bot should make use of "Privileged Gateway Intents".
 #
 # Enabling this means that you need to enable it for the bot (Discord application) as well,
diff --git a/roles/matrix-bridge-appservice-discord/tasks/setup_install.yml b/roles/matrix-bridge-appservice-discord/tasks/setup_install.yml
index 935d07eb..8bf50e28 100644
--- a/roles/matrix-bridge-appservice-discord/tasks/setup_install.yml
+++ b/roles/matrix-bridge-appservice-discord/tasks/setup_install.yml
@@ -1,5 +1,31 @@
 ---
 
+- set_fact:
+    matrix_appservice_discord_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_appservice_discord_sqlite_database_path_local }}"
+      register: matrix_appservice_discord_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_appservice_discord_sqlite_database_path_local }}"
+              dst: "{{ matrix_appservice_discord_database_connString }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_appservice_discord_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-appservice-discord.service']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_appservice_discord_requires_restart: true
+      when: "matrix_appservice_discord_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_appservice_discord_database_engine == 'postgres'"
+
 - name: Ensure Appservice Discord image is pulled
   docker_image:
     name: "{{ matrix_appservice_discord_docker_image }}"
@@ -80,3 +106,9 @@
   service:
     daemon_reload: yes
   when: "matrix_appservice_discord_systemd_service_result.changed"
+
+- name: Ensure matrix-appservice-discord.service restarted, if necessary
+  service:
+    name: "matrix-appservice-discord.service"
+    state: restarted
+  when: "matrix_appservice_discord_requires_restart|bool"
diff --git a/roles/matrix-bridge-appservice-discord/tasks/validate_config.yml b/roles/matrix-bridge-appservice-discord/tasks/validate_config.yml
index b0713a43..73253ba0 100644
--- a/roles/matrix-bridge-appservice-discord/tasks/validate_config.yml
+++ b/roles/matrix-bridge-appservice-discord/tasks/validate_config.yml
@@ -20,3 +20,7 @@
   when: "item.old in vars"
   with_items:
     - {'old': 'matrix_appservice_discord_container_expose_client_server_api_port', 'new': '<superseded by matrix_appservice_discord_container_http_host_bind_port>'}
+
+- name: Require a valid database engine
+  fail: msg="`matrix_appservice_discord_database_engine` needs to be either 'sqlite' or 'postgres'"
+  when: "matrix_appservice_discord_database_engine not in ['sqlite', 'postgres']"
diff --git a/roles/matrix-bridge-appservice-discord/templates/config.yaml.j2 b/roles/matrix-bridge-appservice-discord/templates/config.yaml.j2
index b99f522a..b2ecd198 100644
--- a/roles/matrix-bridge-appservice-discord/templates/config.yaml.j2
+++ b/roles/matrix-bridge-appservice-discord/templates/config.yaml.j2
@@ -58,8 +58,11 @@ database:
   # If you are migrating, see https://github.com/Half-Shot/matrix-appservice-discord/blob/master/docs/howto.md#migrate-to-postgres-from-sqlite
   # WARNING: You will almost certainly be fine with sqlite unless your bridge
   # is in heavy demand and you suffer from IO slowness.
-  filename: "/data/discord.db"
-  # connString: "postgresql://user:password@localhost/database_name"
+  {% if matrix_appservice_discord_database_engine == 'sqlite' %}
+  filename: {{ matrix_appservice_discord_database_filename|to_json }}
+  {% else %}
+  connString: {{ matrix_appservice_discord_database_connString|to_json }}
+  {% endif %}
 room:
   # Set the default visibility of alias rooms, defaults to "public".
   # One of: "public", "private"
diff --git a/roles/matrix-bridge-appservice-irc/defaults/main.yml b/roles/matrix-bridge-appservice-irc/defaults/main.yml
index 7ff2d46a..0b671e76 100644
--- a/roles/matrix-bridge-appservice-irc/defaults/main.yml
+++ b/roles/matrix-bridge-appservice-irc/defaults/main.yml
@@ -16,6 +16,25 @@ matrix_appservice_irc_homeserver_domain: '{{ matrix_domain }}'
 matrix_appservice_irc_homeserver_enablePresence: true
 matrix_appservice_irc_appservice_address: 'http://matrix-appservice-irc:9999'
 
+matrix_appservice_irc_database_engine: nedb
+matrix_appservice_irc_database_username: matrix_appservice_irc
+matrix_appservice_irc_database_password: ~
+matrix_appservice_irc_database_hostname: 'matrix-postgres'
+matrix_appservice_irc_database_port: 5432
+matrix_appservice_irc_database_name: matrix_appservice_irc
+
+# This is just the Postgres connection string, if Postgres is used.
+# Naming clashes with `matrix_appservice_irc_database_connectionString` somewhat.
+matrix_appservice_irc_database_connection_string: 'postgresql://{{ matrix_appservice_irc_database_username }}:{{ matrix_appservice_irc_database_password }}@{{ matrix_appservice_irc_database_hostname }}:{{ matrix_appservice_irc_database_port }}/{{ matrix_appservice_irc_database_name }}?sslmode=disable'
+
+# This is what actually goes into `database.connectionString` for the bridge.
+matrix_appservice_irc_database_connectionString: "{{
+	{
+		'nedb': 'nedb:///data',
+		'postgres': matrix_appservice_irc_database_connection_string,
+	}[matrix_appservice_irc_database_engine]
+}}"
+
 matrix_appservice_irc_ircService_servers: []
 
 # Example of `matrix_appservice_irc_ircService_servers` with one server (and all its options):
diff --git a/roles/matrix-bridge-appservice-irc/tasks/migrate_nedb_to_postgres.yml b/roles/matrix-bridge-appservice-irc/tasks/migrate_nedb_to_postgres.yml
new file mode 100644
index 00000000..3fab195a
--- /dev/null
+++ b/roles/matrix-bridge-appservice-irc/tasks/migrate_nedb_to_postgres.yml
@@ -0,0 +1,64 @@
+- name: Fail if Postgres not enabled
+  fail:
+    msg: "Postgres via the matrix-postgres role is not enabled (`matrix_postgres_enabled`). Cannot migrate."
+  when: "not matrix_postgres_enabled|bool"
+
+# Defaults
+
+- name: Set postgres_start_wait_time, if not provided
+  set_fact:
+    postgres_start_wait_time: 15
+  when: "postgres_start_wait_time|default('') == ''"
+
+# Actual import work
+
+- name: Ensure matrix-postgres is started
+  service:
+    name: matrix-postgres
+    state: started
+    daemon_reload: yes
+  register: matrix_postgres_service_start_result
+
+- name: Wait a bit, so that Postgres can start
+  wait_for:
+    timeout: "{{ postgres_start_wait_time }}"
+  delegate_to: 127.0.0.1
+  become: false
+  when: "matrix_postgres_service_start_result.changed|bool"
+
+- name: Ensure matrix-appservice-irc is stopped
+  service:
+    name: matrix-appservice-irc
+    state: stopped
+
+- name: Import appservice-irc NeDB database into Postgres
+  command:
+    cmd: >-
+      {{ matrix_host_command_docker }} run
+      --rm
+      --user={{ matrix_user_uid }}:{{ matrix_user_gid }}
+      --cap-drop=ALL
+      --network={{ matrix_docker_network }}
+      --mount type=bind,src={{ matrix_appservice_irc_data_path }},dst=/data
+      --entrypoint=/bin/sh
+      {{ matrix_appservice_irc_docker_image }}
+      -c
+      '/usr/local/bin/node /app/lib/scripts/migrate-db-to-pgres.js --dbdir /data --privateKey /data/passkey.pem --connectionString {{ matrix_appservice_irc_database_connection_string }}'
+
+- name: Archive NeDB database files
+  command:
+    cmd: "mv {{ matrix_appservice_irc_data_path }}/{{ item }} {{ matrix_appservice_irc_data_path }}/{{ item }}.backup"
+  with_items:
+    - rooms.db
+    - users.db
+
+- name: Inject result
+  set_fact:
+    matrix_playbook_runtime_results: |
+      {{
+        matrix_playbook_runtime_results|default([])
+        +
+        [
+          "NOTE: Your appservice-irc database files have been imported into Postgres. The original database files have been moved from `{{ matrix_appservice_irc_data_path }}/*.db` to `{{ matrix_appservice_irc_data_path }}/*.db.backup`. When you've confirmed that the import went well and everything works, you should be able to safely delete these files."
+        ]
+      }}
diff --git a/roles/matrix-bridge-appservice-irc/tasks/setup_install.yml b/roles/matrix-bridge-appservice-irc/tasks/setup_install.yml
index 5e313347..00568c0d 100644
--- a/roles/matrix-bridge-appservice-irc/tasks/setup_install.yml
+++ b/roles/matrix-bridge-appservice-irc/tasks/setup_install.yml
@@ -1,12 +1,5 @@
 ---
 
-- name: Ensure Appservice IRC image is pulled
-  docker_image:
-    name: "{{ matrix_appservice_irc_docker_image }}"
-    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
-    force_source: "{{ matrix_appservice_irc_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
-    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_appservice_irc_docker_image_force_pull }}"
-
 - name: Ensure Appservice IRC paths exist
   file:
     path: "{{ item }}"
@@ -24,25 +17,48 @@
     path: "{{ matrix_appservice_irc_base_path }}/passkey.pem"
   register: matrix_appservice_irc_stat_passkey
 
-- name: (Data relocation) Ensure matrix-appservice-irc.service is stopped
-  service:
-    name: matrix-appservice-irc
-    state: stopped
-    daemon_reload: yes
-  failed_when: false
+- block:
+    - name: (Data relocation) Ensure matrix-appservice-irc.service is stopped
+      service:
+        name: matrix-appservice-irc
+        state: stopped
+        daemon_reload: yes
+      failed_when: false
+
+    - name: (Data relocation) Move AppService IRC passkey.pem file to ./data directory
+      command: "mv {{ matrix_appservice_irc_base_path }}/passkey.pem {{ matrix_appservice_irc_data_path }}/passkey.pem"
+
+    - name: (Data relocation) Move AppService IRC database files to ./data directory
+      command: "mv {{ matrix_appservice_irc_base_path }}/{{ item }} {{ matrix_appservice_irc_data_path }}/{{ item }}"
+      with_items:
+        - rooms.db
+        - users.db
+      failed_when: false
   when: "matrix_appservice_irc_stat_passkey.stat.exists"
 
-- name: (Data relocation) Move AppService IRC passkey.pem file to ./data directory
-  command: "mv {{ matrix_appservice_irc_base_path }}/passkey.pem {{ matrix_appservice_irc_data_path }}/passkey.pem"
-  when: "matrix_appservice_irc_stat_passkey.stat.exists"
+- set_fact:
+    matrix_appservice_irc_requires_restart: false
 
-- name: (Data relocation) Move AppService IRC database files to ./data directory
-  command: "mv {{ matrix_appservice_irc_base_path }}/{{ item }} {{ matrix_appservice_irc_data_path }}/{{ item }}"
-  with_items:
-    - rooms.db
-    - users.db
-  failed_when: false
-  when: "matrix_appservice_irc_stat_passkey.stat.exists"
+- block:
+    - name: Check if a nedb database already exists
+      stat:
+        path: "{{ matrix_appservice_irc_data_path }}/users.db"
+      register: matrix_appservice_irc_nedb_database_path_local_stat_result
+
+    - block:
+        - import_tasks: "{{ role_path }}/tasks/migrate_nedb_to_postgres.yml"
+
+        - set_fact:
+            matrix_appservice_irc_requires_restart: true
+      when: "matrix_appservice_irc_nedb_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_appservice_irc_database_engine == 'postgres'"
+
+- name: Ensure Appservice IRC image is pulled
+  docker_image:
+    name: "{{ matrix_appservice_irc_docker_image }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_appservice_irc_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
+    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_appservice_irc_docker_image_force_pull }}"
 
 - name: Ensure Matrix Appservice IRC config installed
   copy:
@@ -147,3 +163,9 @@
   service:
     daemon_reload: yes
   when: "matrix_appservice_irc_systemd_service_result.changed"
+
+- name: Ensure matrix-appservice-irc.service restarted, if necessary
+  service:
+    name: "matrix-appservice-irc.service"
+    state: restarted
+  when: "matrix_appservice_irc_requires_restart|bool"
diff --git a/roles/matrix-bridge-appservice-irc/templates/config.yaml.j2 b/roles/matrix-bridge-appservice-irc/templates/config.yaml.j2
index 3daa1898..94bbda7b 100644
--- a/roles/matrix-bridge-appservice-irc/templates/config.yaml.j2
+++ b/roles/matrix-bridge-appservice-irc/templates/config.yaml.j2
@@ -127,8 +127,8 @@ advanced:
 # Use an external database to store bridge state.
 database:
   # database engine (must be 'postgres' or 'nedb'). Default: nedb
-  engine: "nedb"
+  engine: {{ matrix_appservice_irc_database_engine|to_json }}
   # Either a PostgreSQL connection string, or a path to the NeDB storage directory.
   # For postgres, it must start with postgres://
   # For NeDB, it must start with nedb://. The path is relative to the project directory.
-  connectionString: "nedb:///data"
+  connectionString: {{ matrix_appservice_irc_database_connectionString|to_json }}
diff --git a/roles/matrix-bridge-appservice-slack/defaults/main.yml b/roles/matrix-bridge-appservice-slack/defaults/main.yml
index f2cfd8f9..28646a3c 100644
--- a/roles/matrix-bridge-appservice-slack/defaults/main.yml
+++ b/roles/matrix-bridge-appservice-slack/defaults/main.yml
@@ -45,6 +45,26 @@ matrix_appservice_slack_appservice_token: ''
 matrix_appservice_slack_homeserver_token: ''
 matrix_appservice_slack_id_token: ''
 
+matrix_appservice_slack_database_engine: nedb
+matrix_appservice_slack_database_username: matrix_appservice_slack
+matrix_appservice_slack_database_password: ~
+matrix_appservice_slack_database_hostname: 'matrix-postgres'
+matrix_appservice_slack_database_port: 5432
+matrix_appservice_slack_database_name: matrix_appservice_slack
+
+# This is just the Postgres connection string, if Postgres is used.
+# Naming clashes with `matrix_appservice_slack_database_connectionString` somewhat.
+matrix_appservice_slack_database_connection_string: 'postgresql://{{ matrix_appservice_slack_database_username }}:{{ matrix_appservice_slack_database_password }}@{{ matrix_appservice_slack_database_hostname }}:{{ matrix_appservice_slack_database_port }}/{{ matrix_appservice_slack_database_name }}?sslmode=disable'
+
+# This is what actually goes into `database.connectionString` for the bridge.
+matrix_appservice_slack_database_connectionString: "{{
+	{
+		'nedb': 'nedb:///data',
+		'postgres': matrix_appservice_slack_database_connection_string,
+	}[matrix_appservice_slack_database_engine]
+}}"
+
+
 matrix_appservice_slack_configuration_yaml: "{{ lookup('template', 'templates/config.yaml.j2') }}"
 
 matrix_appservice_slack_configuration_extension_yaml: |
diff --git a/roles/matrix-bridge-appservice-slack/tasks/migrate_nedb_to_postgres.yml b/roles/matrix-bridge-appservice-slack/tasks/migrate_nedb_to_postgres.yml
new file mode 100644
index 00000000..fedad977
--- /dev/null
+++ b/roles/matrix-bridge-appservice-slack/tasks/migrate_nedb_to_postgres.yml
@@ -0,0 +1,66 @@
+- name: Fail if Postgres not enabled
+  fail:
+    msg: "Postgres via the matrix-postgres role is not enabled (`matrix_postgres_enabled`). Cannot migrate."
+  when: "not matrix_postgres_enabled|bool"
+
+# Defaults
+
+- name: Set postgres_start_wait_time, if not provided
+  set_fact:
+    postgres_start_wait_time: 15
+  when: "postgres_start_wait_time|default('') == ''"
+
+# Actual import work
+
+- name: Ensure matrix-postgres is started
+  service:
+    name: matrix-postgres
+    state: started
+    daemon_reload: yes
+  register: matrix_postgres_service_start_result
+
+- name: Wait a bit, so that Postgres can start
+  wait_for:
+    timeout: "{{ postgres_start_wait_time }}"
+  delegate_to: 127.0.0.1
+  become: false
+  when: "matrix_postgres_service_start_result.changed|bool"
+
+- name: Ensure matrix-appservice-slack is stopped
+  service:
+    name: matrix-appservice-slack
+    state: stopped
+
+- name: Import appservice-slack NeDB database into Postgres
+  command:
+    cmd: >-
+      {{ matrix_host_command_docker }} run
+      --rm
+      --user={{ matrix_user_uid }}:{{ matrix_user_gid }}
+      --cap-drop=ALL
+      --network={{ matrix_docker_network }}
+      --mount type=bind,src={{ matrix_appservice_slack_data_path }},dst=/data
+      --entrypoint=/bin/sh
+      {{ matrix_appservice_slack_docker_image }}
+      -c
+      '/usr/local/bin/node /usr/src/app/lib/scripts/migrateToPostgres.js --dbdir /data --connectionString {{ matrix_appservice_slack_database_connection_string }}'
+
+- name: Archive NeDB database files
+  command:
+    cmd: "mv {{ matrix_appservice_slack_data_path }}/{{ item }} {{ matrix_appservice_slack_data_path }}/{{ item }}.backup"
+  with_items:
+    - teams.db
+    - room-store.db
+    - user-store.db
+    - event-store.db
+
+- name: Inject result
+  set_fact:
+    matrix_playbook_runtime_results: |
+      {{
+        matrix_playbook_runtime_results|default([])
+        +
+        [
+          "NOTE: Your appservice-slack database files have been imported into Postgres. The original database files have been moved from `{{ matrix_appservice_slack_data_path }}/*.db` to `{{ matrix_appservice_slack_data_path }}/*.db.backup`. When you've confirmed that the import went well and everything works, you should be able to safely delete these files."
+        ]
+      }}
diff --git a/roles/matrix-bridge-appservice-slack/tasks/setup_install.yml b/roles/matrix-bridge-appservice-slack/tasks/setup_install.yml
index 94e0fedf..29b0f39e 100644
--- a/roles/matrix-bridge-appservice-slack/tasks/setup_install.yml
+++ b/roles/matrix-bridge-appservice-slack/tasks/setup_install.yml
@@ -1,12 +1,5 @@
 ---
 
-- name: Ensure Appservice Slack image is pulled
-  docker_image:
-    name: "{{ matrix_appservice_slack_docker_image }}"
-    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
-    force_source: "{{ matrix_appservice_slack_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
-    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_appservice_slack_docker_image_force_pull }}"
-
 - name: Ensure AppService Slack paths exist
   file:
     path: "{{ item }}"
@@ -19,6 +12,30 @@
     - "{{ matrix_appservice_slack_config_path }}"
     - "{{ matrix_appservice_slack_data_path }}"
 
+- set_fact:
+    matrix_appservice_slack_requires_restart: false
+
+- block:
+    - name: Check if a nedb database already exists
+      stat:
+        path: "{{ matrix_appservice_slack_data_path }}/teams.db"
+      register: matrix_appservice_slack_nedb_database_path_local_stat_result
+
+    - block:
+        - import_tasks: "{{ role_path }}/tasks/migrate_nedb_to_postgres.yml"
+
+        - set_fact:
+            matrix_appservice_slack_requires_restart: true
+      when: "matrix_appservice_slack_nedb_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_appservice_slack_database_engine == 'postgres'"
+
+- name: Ensure Appservice Slack image is pulled
+  docker_image:
+    name: "{{ matrix_appservice_slack_docker_image }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_appservice_slack_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
+    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_appservice_slack_docker_image_force_pull }}"
+
 - name: Ensure Matrix Appservice Slack config installed
   copy:
     content: "{{ matrix_appservice_slack_configuration|to_nice_yaml }}"
@@ -46,3 +63,9 @@
   service:
     daemon_reload: yes
   when: "matrix_appservice_slack_systemd_service_result.changed"
+
+- name: Ensure matrix-appservice-slack.service restarted, if necessary
+  service:
+    name: "matrix-appservice-slack.service"
+    state: restarted
+  when: "matrix_appservice_slack_requires_restart|bool"
diff --git a/roles/matrix-bridge-appservice-slack/tasks/validate_config.yml b/roles/matrix-bridge-appservice-slack/tasks/validate_config.yml
index 5da5f947..8af10f2f 100644
--- a/roles/matrix-bridge-appservice-slack/tasks/validate_config.yml
+++ b/roles/matrix-bridge-appservice-slack/tasks/validate_config.yml
@@ -9,4 +9,4 @@
     - "matrix_appservice_slack_control_room_id"
     - "matrix_appservice_slack_appservice_token"
     - "matrix_appservice_slack_homeserver_token"
-    - "matrix_appservice_slack_id_token"
\ No newline at end of file
+    - "matrix_appservice_slack_id_token"
diff --git a/roles/matrix-bridge-appservice-slack/templates/config.yaml.j2 b/roles/matrix-bridge-appservice-slack/templates/config.yaml.j2
index 8f48d317..bf8072c1 100644
--- a/roles/matrix-bridge-appservice-slack/templates/config.yaml.j2
+++ b/roles/matrix-bridge-appservice-slack/templates/config.yaml.j2
@@ -9,6 +9,12 @@ homeserver:
     url: "{{ matrix_appservice_slack_homeserver_url }}"
     server_name: "{{ matrix_domain }}"
 
+{% if matrix_appservice_slack_database_engine == 'nedb' %}
 dbdir: "/data"
+{% else %}
+db:
+    engine: {{ matrix_appservice_slack_database_engine|to_json }}
+    connectionString: {{ matrix_appservice_slack_database_connectionString|to_json }}
+{% endif %}
 
 matrix_admin_room: "{{ matrix_appservice_slack_control_room_id }}"
diff --git a/roles/matrix-bridge-mautrix-facebook/defaults/main.yml b/roles/matrix-bridge-mautrix-facebook/defaults/main.yml
index 1547ad71..580934db 100644
--- a/roles/matrix-bridge-mautrix-facebook/defaults/main.yml
+++ b/roles/matrix-bridge-mautrix-facebook/defaults/main.yml
@@ -32,6 +32,35 @@ matrix_mautrix_facebook_systemd_wanted_services_list: []
 matrix_mautrix_facebook_appservice_token: ''
 matrix_mautrix_facebook_homeserver_token: ''
 
+
+# Database-related configuration fields.
+#
+# To use SQLite, stick to these defaults.
+#
+# To use Postgres:
+# - change the engine (`matrix_mautrix_facebook_database_engine: 'postgres'`)
+# - adjust your database credentials via the `matrix_mautrix_facebook_postgres_*` variables
+matrix_mautrix_facebook_database_engine: 'sqlite'
+
+matrix_mautrix_facebook_sqlite_database_path_local: "{{ matrix_mautrix_facebook_data_path }}/mautrix-facebook.db"
+matrix_mautrix_facebook_sqlite_database_path_in_container: "/data/mautrix-facebook.db"
+
+matrix_mautrix_facebook_database_username: 'matrix_mautrix_facebook'
+matrix_mautrix_facebook_database_password: 'some-password'
+matrix_mautrix_facebook_database_hostname: 'matrix-postgres'
+matrix_mautrix_facebook_database_port: 5432
+matrix_mautrix_facebook_database_name: 'matrix_mautrix_facebook'
+
+matrix_mautrix_facebook_database_connection_string: 'postgresql://{{ matrix_mautrix_facebook_database_username }}:{{ matrix_mautrix_facebook_database_password }}@{{ matrix_mautrix_facebook_database_hostname }}:{{ matrix_mautrix_facebook_database_port }}/{{ matrix_mautrix_facebook_database_name }}'
+
+matrix_mautrix_facebook_appservice_database: "{{
+	{
+		'sqlite': ('sqlite://' + matrix_mautrix_facebook_sqlite_database_path_in_container),
+		'postgres': matrix_mautrix_facebook_database_connection_string,
+	}[matrix_mautrix_facebook_database_engine]
+}}"
+
+
 # Can be set to enable automatic double-puppeting via Shared Secret Auth (https://github.com/devture/matrix-synapse-shared-secret-auth).
 matrix_mautrix_facebook_login_shared_secret: ''
 
diff --git a/roles/matrix-bridge-mautrix-facebook/tasks/setup_install.yml b/roles/matrix-bridge-mautrix-facebook/tasks/setup_install.yml
index 638854e2..7f310446 100644
--- a/roles/matrix-bridge-mautrix-facebook/tasks/setup_install.yml
+++ b/roles/matrix-bridge-mautrix-facebook/tasks/setup_install.yml
@@ -8,6 +8,32 @@
       The matrix-bridge-mautrix-facebook role needs to execute before the matrix-synapse role.
   when: "matrix_synapse_role_executed|default(False)"
 
+- set_fact:
+    matrix_mautrix_facebook_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_mautrix_facebook_sqlite_database_path_local }}"
+      register: matrix_mautrix_facebook_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_mautrix_facebook_sqlite_database_path_local }}"
+              dst: "{{ matrix_mautrix_facebook_database_connection_string }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_mautrix_facebook_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-mautrix-facebook.service']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_mautrix_facebook_requires_restart: true
+      when: "matrix_mautrix_facebook_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_mautrix_facebook_database_engine == 'postgres'"
+
 - name: Ensure Mautrix Facebook image is pulled
   docker_image:
     name: "{{ matrix_mautrix_facebook_docker_image }}"
@@ -94,3 +120,9 @@
   service:
     daemon_reload: yes
   when: "matrix_mautrix_facebook_systemd_service_result.changed"
+
+- name: Ensure matrix-mautrix-facebook.service restarted, if necessary
+  service:
+    name: "matrix-mautrix-facebook.service"
+    state: restarted
+  when: "matrix_mautrix_facebook_requires_restart|bool"
diff --git a/roles/matrix-bridge-mautrix-facebook/templates/config.yaml.j2 b/roles/matrix-bridge-mautrix-facebook/templates/config.yaml.j2
index 9d8de2d5..09287362 100644
--- a/roles/matrix-bridge-mautrix-facebook/templates/config.yaml.j2
+++ b/roles/matrix-bridge-mautrix-facebook/templates/config.yaml.j2
@@ -27,7 +27,7 @@ appservice:
     # Format examples:
     #   SQLite:   sqlite:///filename.db
     #   Postgres: postgres://username:password@hostname/dbname
-    database: sqlite:////data/mautrix-facebook.db
+    database: {{ matrix_mautrix_facebook_appservice_database|to_json }}
 
     # Public part of web server for out-of-Matrix interaction with the bridge.
     public:
diff --git a/roles/matrix-bridge-mautrix-facebook/templates/systemd/matrix-mautrix-facebook.service.j2 b/roles/matrix-bridge-mautrix-facebook/templates/systemd/matrix-mautrix-facebook.service.j2
index 18184650..caa52eb5 100644
--- a/roles/matrix-bridge-mautrix-facebook/templates/systemd/matrix-mautrix-facebook.service.j2
+++ b/roles/matrix-bridge-mautrix-facebook/templates/systemd/matrix-mautrix-facebook.service.j2
@@ -18,6 +18,7 @@ ExecStartPre={{ matrix_host_command_docker }} run --rm --name matrix-mautrix-fac
 			--log-driver=none \
 			--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
 			--cap-drop=ALL \
+			--network={{ matrix_docker_network }} \
 			-v {{ matrix_mautrix_facebook_config_path }}:/config:z \
 			-v {{ matrix_mautrix_facebook_data_path }}:/data:z \
 			{{ matrix_mautrix_facebook_docker_image }} \
diff --git a/roles/matrix-bridge-mautrix-hangouts/defaults/main.yml b/roles/matrix-bridge-mautrix-hangouts/defaults/main.yml
index ab670052..984bec48 100644
--- a/roles/matrix-bridge-mautrix-hangouts/defaults/main.yml
+++ b/roles/matrix-bridge-mautrix-hangouts/defaults/main.yml
@@ -39,6 +39,35 @@ matrix_mautrix_hangouts_systemd_wanted_services_list: []
 matrix_mautrix_hangouts_appservice_token: ''
 matrix_mautrix_hangouts_homeserver_token: ''
 
+
+# Database-related configuration fields.
+#
+# To use SQLite, stick to these defaults.
+#
+# To use Postgres:
+# - change the engine (`matrix_mautrix_hangouts_database_engine: 'postgres'`)
+# - adjust your database credentials via the `matrix_mautrix_hangouts_postgres_*` variables
+matrix_mautrix_hangouts_database_engine: 'sqlite'
+
+matrix_mautrix_hangouts_sqlite_database_path_local: "{{ matrix_mautrix_hangouts_data_path }}/mautrix-hangouts.db"
+matrix_mautrix_hangouts_sqlite_database_path_in_container: "/data/mautrix-hangouts.db"
+
+matrix_mautrix_hangouts_database_username: 'matrix_mautrix_hangouts'
+matrix_mautrix_hangouts_database_password: 'some-password'
+matrix_mautrix_hangouts_database_hostname: 'matrix-postgres'
+matrix_mautrix_hangouts_database_port: 5432
+matrix_mautrix_hangouts_database_name: 'matrix_mautrix_hangouts'
+
+matrix_mautrix_hangouts_database_connection_string: 'postgresql://{{ matrix_mautrix_hangouts_database_username }}:{{ matrix_mautrix_hangouts_database_password }}@{{ matrix_mautrix_hangouts_database_hostname }}:{{ matrix_mautrix_hangouts_database_port }}/{{ matrix_mautrix_hangouts_database_name }}'
+
+matrix_mautrix_hangouts_appservice_database: "{{
+	{
+		'sqlite': ('sqlite://' + matrix_mautrix_hangouts_sqlite_database_path_in_container),
+		'postgres': matrix_mautrix_hangouts_database_connection_string,
+	}[matrix_mautrix_hangouts_database_engine]
+}}"
+
+
 # Can be set to enable automatic double-puppeting via Shared Secret Auth (https://github.com/devture/matrix-synapse-shared-secret-auth).
 matrix_mautrix_hangouts_login_shared_secret: ''
 
diff --git a/roles/matrix-bridge-mautrix-hangouts/tasks/setup_install.yml b/roles/matrix-bridge-mautrix-hangouts/tasks/setup_install.yml
index eec5e006..15af9626 100644
--- a/roles/matrix-bridge-mautrix-hangouts/tasks/setup_install.yml
+++ b/roles/matrix-bridge-mautrix-hangouts/tasks/setup_install.yml
@@ -8,6 +8,32 @@
       The matrix-bridge-mautrix-hangouts role needs to execute before the matrix-synapse role.
   when: "matrix_synapse_role_executed|default(False)"
 
+- set_fact:
+    matrix_mautrix_hangouts_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_mautrix_hangouts_sqlite_database_path_local }}"
+      register: matrix_mautrix_hangouts_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_mautrix_hangouts_sqlite_database_path_local }}"
+              dst: "{{ matrix_mautrix_hangouts_database_connection_string }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_mautrix_hangouts_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-mautrix-hangouts.service']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_mautrix_hangouts_requires_restart: true
+      when: "matrix_mautrix_hangouts_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_mautrix_hangouts_database_engine == 'postgres'"
+
 - name: Ensure Mautrix Hangouts image is pulled
   docker_image:
     name: "{{ matrix_mautrix_hangouts_docker_image }}"
@@ -93,3 +119,9 @@
   service:
     daemon_reload: yes
   when: "matrix_mautrix_hangouts_systemd_service_result.changed"
+
+- name: Ensure matrix-mautrix-hangouts.service restarted, if necessary
+  service:
+    name: "matrix-mautrix-hangouts.service"
+    state: restarted
+  when: "matrix_mautrix_hangouts_requires_restart|bool"
diff --git a/roles/matrix-bridge-mautrix-hangouts/templates/config.yaml.j2 b/roles/matrix-bridge-mautrix-hangouts/templates/config.yaml.j2
index f274b203..cc2ca90b 100644
--- a/roles/matrix-bridge-mautrix-hangouts/templates/config.yaml.j2
+++ b/roles/matrix-bridge-mautrix-hangouts/templates/config.yaml.j2
@@ -27,7 +27,7 @@ appservice:
     # Format examples:
     #   SQLite:   sqlite:///filename.db
     #   Postgres: postgres://username:password@hostname/dbname
-    database: sqlite:////data/mautrix-hangouts.db
+    database: {{ matrix_mautrix_hangouts_appservice_database|to_json }}
 
     # The unique ID of this appservice.
     id: hangouts
diff --git a/roles/matrix-bridge-mautrix-hangouts/templates/systemd/matrix-mautrix-hangouts.service.j2 b/roles/matrix-bridge-mautrix-hangouts/templates/systemd/matrix-mautrix-hangouts.service.j2
index 26280da3..39559190 100644
--- a/roles/matrix-bridge-mautrix-hangouts/templates/systemd/matrix-mautrix-hangouts.service.j2
+++ b/roles/matrix-bridge-mautrix-hangouts/templates/systemd/matrix-mautrix-hangouts.service.j2
@@ -18,6 +18,7 @@ ExecStartPre={{ matrix_host_command_docker }} run --rm --name matrix-mautrix-han
 			--log-driver=none \
 			--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
 			--cap-drop=ALL \
+			--network={{ matrix_docker_network }} \
 			-v {{ matrix_mautrix_hangouts_config_path }}:/config:z \
 			-v {{ matrix_mautrix_hangouts_data_path }}:/data:z \
 			{{ matrix_mautrix_hangouts_docker_image }} \
diff --git a/roles/matrix-bridge-mautrix-telegram/defaults/main.yml b/roles/matrix-bridge-mautrix-telegram/defaults/main.yml
index b6f4ef5b..ceebd3ec 100644
--- a/roles/matrix-bridge-mautrix-telegram/defaults/main.yml
+++ b/roles/matrix-bridge-mautrix-telegram/defaults/main.yml
@@ -43,6 +43,35 @@ matrix_mautrix_telegram_systemd_wanted_services_list: []
 matrix_mautrix_telegram_appservice_token: ''
 matrix_mautrix_telegram_homeserver_token: ''
 
+
+# Database-related configuration fields.
+#
+# To use SQLite, stick to these defaults.
+#
+# To use Postgres:
+# - change the engine (`matrix_mautrix_telegram_database_engine: 'postgres'`)
+# - adjust your database credentials via the `matrix_mautrix_telegram_postgres_*` variables
+matrix_mautrix_telegram_database_engine: 'sqlite'
+
+matrix_mautrix_telegram_sqlite_database_path_local: "{{ matrix_mautrix_telegram_data_path }}/mautrix-telegram.db"
+matrix_mautrix_telegram_sqlite_database_path_in_container: "/data/mautrix-telegram.db"
+
+matrix_mautrix_telegram_database_username: 'matrix_mautrix_telegram'
+matrix_mautrix_telegram_database_password: 'some-password'
+matrix_mautrix_telegram_database_hostname: 'matrix-postgres'
+matrix_mautrix_telegram_database_port: 5432
+matrix_mautrix_telegram_database_name: 'matrix_mautrix_telegram'
+
+matrix_mautrix_telegram_database_connection_string: 'postgresql://{{ matrix_mautrix_telegram_database_username }}:{{ matrix_mautrix_telegram_database_password }}@{{ matrix_mautrix_telegram_database_hostname }}:{{ matrix_mautrix_telegram_database_port }}/{{ matrix_mautrix_telegram_database_name }}'
+
+matrix_mautrix_telegram_appservice_database: "{{
+	{
+		'sqlite': ('sqlite://' + matrix_mautrix_telegram_sqlite_database_path_in_container),
+		'postgres': matrix_mautrix_telegram_database_connection_string,
+	}[matrix_mautrix_telegram_database_engine]
+}}"
+
+
 # Can be set to enable automatic double-puppeting via Shared Secret Auth (https://github.com/devture/matrix-synapse-shared-secret-auth).
 matrix_mautrix_telegram_login_shared_secret: ''
 
diff --git a/roles/matrix-bridge-mautrix-telegram/tasks/setup_install.yml b/roles/matrix-bridge-mautrix-telegram/tasks/setup_install.yml
index 9dc38ec2..6a37974a 100644
--- a/roles/matrix-bridge-mautrix-telegram/tasks/setup_install.yml
+++ b/roles/matrix-bridge-mautrix-telegram/tasks/setup_install.yml
@@ -8,6 +8,32 @@
       The matrix-bridge-mautrix-telegram role needs to execute before the matrix-synapse role.
   when: "matrix_synapse_role_executed|default(False)"
 
+- set_fact:
+    matrix_mautrix_telegram_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_mautrix_telegram_sqlite_database_path_local }}"
+      register: matrix_mautrix_telegram_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_mautrix_telegram_sqlite_database_path_local }}"
+              dst: "{{ matrix_mautrix_telegram_database_connection_string }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_mautrix_telegram_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-mautrix-telegram.service']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_mautrix_telegram_requires_restart: true
+      when: "matrix_mautrix_telegram_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_mautrix_telegram_database_engine == 'postgres'"
+
 - name: Ensure Mautrix Telegram image is pulled
   docker_image:
     name: "{{ matrix_mautrix_telegram_docker_image }}"
@@ -71,3 +97,9 @@
   service:
     daemon_reload: yes
   when: "matrix_mautrix_telegram_systemd_service_result.changed"
+
+- name: Ensure matrix-mautrix-telegram.service restarted, if necessary
+  service:
+    name: "matrix-mautrix-telegram.service"
+    state: restarted
+  when: "matrix_mautrix_telegram_requires_restart|bool"
diff --git a/roles/matrix-bridge-mautrix-telegram/templates/config.yaml.j2 b/roles/matrix-bridge-mautrix-telegram/templates/config.yaml.j2
index 1a4ac43e..52efba02 100644
--- a/roles/matrix-bridge-mautrix-telegram/templates/config.yaml.j2
+++ b/roles/matrix-bridge-mautrix-telegram/templates/config.yaml.j2
@@ -27,7 +27,7 @@ appservice:
     # Format examples:
     #   SQLite:   sqlite:///filename.db
     #   Postgres: postgres://username:password@hostname/dbname
-    database: sqlite:////data/mautrix-telegram.db
+    database: {{ matrix_mautrix_telegram_appservice_database|to_json }}
 
     # Public part of web server for out-of-Matrix interaction with the bridge.
     # Used for things like login if the user wants to make sure the 2FA password isn't stored in
diff --git a/roles/matrix-bridge-mautrix-whatsapp/defaults/main.yml b/roles/matrix-bridge-mautrix-whatsapp/defaults/main.yml
index e9929f96..0d4f9852 100644
--- a/roles/matrix-bridge-mautrix-whatsapp/defaults/main.yml
+++ b/roles/matrix-bridge-mautrix-whatsapp/defaults/main.yml
@@ -27,6 +27,42 @@ matrix_mautrix_whatsapp_systemd_wanted_services_list: []
 matrix_mautrix_whatsapp_appservice_token: ''
 matrix_mautrix_whatsapp_homeserver_token: ''
 
+
+# Database-related configuration fields.
+#
+# To use SQLite, stick to these defaults.
+#
+# To use Postgres:
+# - change the engine (`matrix_mautrix_whatsapp_database_engine: 'postgres'`)
+# - adjust your database credentials via the `matrix_mautrix_whatsapp_postgres_*` variables
+matrix_mautrix_whatsapp_database_engine: 'sqlite'
+
+matrix_mautrix_whatsapp_sqlite_database_path_local: "{{ matrix_mautrix_whatsapp_data_path }}/mautrix-whatsapp.db"
+matrix_mautrix_whatsapp_sqlite_database_path_in_container: "/data/mautrix-whatsapp.db"
+
+matrix_mautrix_whatsapp_database_username: 'matrix_mautrix_whatsapp'
+matrix_mautrix_whatsapp_database_password: 'some-password'
+matrix_mautrix_whatsapp_database_hostname: 'matrix-postgres'
+matrix_mautrix_whatsapp_database_port: 5432
+matrix_mautrix_whatsapp_database_name: 'matrix_mautrix_whatsapp'
+
+matrix_mautrix_whatsapp_database_connection_string: 'postgresql://{{ matrix_mautrix_whatsapp_database_username }}:{{ matrix_mautrix_whatsapp_database_password }}@{{ matrix_mautrix_whatsapp_database_hostname }}:{{ matrix_mautrix_whatsapp_database_port }}/{{ matrix_mautrix_whatsapp_database_name }}'
+
+matrix_mautrix_whatsapp_appservice_database_type: "{{
+	{
+		'sqlite': 'sqlite3',
+		'postgres':'postgres',
+	}[matrix_mautrix_whatsapp_database_engine]
+}}"
+
+matrix_mautrix_whatsapp_appservice_database_uri: "{{
+	{
+		'sqlite': matrix_mautrix_whatsapp_sqlite_database_path_in_container,
+		'postgres': matrix_mautrix_whatsapp_database_connection_string,
+	}[matrix_mautrix_whatsapp_database_engine]
+}}"
+
+
 # Can be set to enable automatic double-puppeting via Shared Secret Auth (https://github.com/devture/matrix-synapse-shared-secret-auth).
 matrix_mautrix_whatsapp_login_shared_secret: ''
 
diff --git a/roles/matrix-bridge-mautrix-whatsapp/tasks/setup_install.yml b/roles/matrix-bridge-mautrix-whatsapp/tasks/setup_install.yml
index 6bd87bbe..8d894a84 100644
--- a/roles/matrix-bridge-mautrix-whatsapp/tasks/setup_install.yml
+++ b/roles/matrix-bridge-mautrix-whatsapp/tasks/setup_install.yml
@@ -8,6 +8,32 @@
       The matrix-bridge-mautrix-whatsapp role needs to execute before the matrix-synapse role.
   when: "matrix_synapse_role_executed|default(False)"
 
+- set_fact:
+    matrix_mautrix_whatsapp_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_mautrix_whatsapp_sqlite_database_path_local }}"
+      register: matrix_mautrix_whatsapp_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_mautrix_whatsapp_sqlite_database_path_local }}"
+              dst: "{{ matrix_mautrix_whatsapp_database_connection_string }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_mautrix_whatsapp_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-mautrix-whatsapp.service']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_mautrix_whatsapp_requires_restart: true
+      when: "matrix_mautrix_whatsapp_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_mautrix_whatsapp_database_engine == 'postgres'"
+
 - name: Ensure Mautrix Whatsapp image is pulled
   docker_image:
     name: "{{ matrix_mautrix_whatsapp_docker_image }}"
@@ -26,12 +52,12 @@
     - "{{ matrix_mautrix_whatsapp_base_path }}"
     - "{{ matrix_mautrix_whatsapp_config_path }}"
     - "{{ matrix_mautrix_whatsapp_data_path }}"
-    
+
 - name: Check if an old database file exists
   stat:
     path: "{{ matrix_mautrix_whatsapp_base_path }}/mautrix-whatsapp.db"
   register: matrix_mautrix_whatsapp_stat_database
-  
+
 - name: Check if an old matrix state file exists
   stat:
     path: "{{ matrix_mautrix_whatsapp_base_path }}/mx-state.json"
@@ -48,7 +74,7 @@
 - name: (Data relocation) Move mautrix-whatsapp database file to ./data directory
   command: "mv {{ matrix_mautrix_whatsapp_base_path }}/mautrix-whatsapp.db {{ matrix_mautrix_whatsapp_data_path }}/mautrix-whatsapp.db"
   when: "matrix_mautrix_whatsapp_stat_database.stat.exists"
-  
+
 - name: (Data relocation) Move mautrix-whatsapp mx-state file to ./data directory
   command: "mv {{ matrix_mautrix_whatsapp_base_path }}/mx-state.json {{ matrix_mautrix_whatsapp_data_path }}/mx-state.json"
   when: "matrix_mautrix_whatsapp_stat_mx_state.stat.exists"
@@ -80,3 +106,9 @@
   service:
     daemon_reload: yes
   when: "matrix_mautrix_whatsapp_systemd_service_result.changed"
+
+- name: Ensure matrix-mautrix-whatsapp.service restarted, if necessary
+  service:
+    name: "matrix-mautrix-whatsapp.service"
+    state: restarted
+  when: "matrix_mautrix_whatsapp_requires_restart|bool"
diff --git a/roles/matrix-bridge-mautrix-whatsapp/templates/config.yaml.j2 b/roles/matrix-bridge-mautrix-whatsapp/templates/config.yaml.j2
index a527a188..89216695 100644
--- a/roles/matrix-bridge-mautrix-whatsapp/templates/config.yaml.j2
+++ b/roles/matrix-bridge-mautrix-whatsapp/templates/config.yaml.j2
@@ -19,11 +19,11 @@ appservice:
     # Database config.
     database:
         # The database type. "sqlite3" and "postgres" are supported.
-        type: sqlite3
+        type: {{ matrix_mautrix_whatsapp_appservice_database_type|to_json }}
         # The database URI.
         #   SQLite: File name is enough. https://github.com/mattn/go-sqlite3#connection-string
         #   Postgres: Connection string. For example, postgres://user:password@host/database
-        uri: mautrix-whatsapp.db
+        uri: {{ matrix_mautrix_whatsapp_appservice_database_uri|to_json }}
         # Maximum number of connections. Mostly relevant for Postgres.
         max_open_conns: 20
         max_idle_conns: 2
diff --git a/roles/matrix-bridge-mx-puppet-discord/defaults/main.yml b/roles/matrix-bridge-mx-puppet-discord/defaults/main.yml
index 268bbf8f..97b20313 100644
--- a/roles/matrix-bridge-mx-puppet-discord/defaults/main.yml
+++ b/roles/matrix-bridge-mx-puppet-discord/defaults/main.yml
@@ -55,6 +55,20 @@ matrix_mx_puppet_discord_homeserver_token: ''
 # Can be set to enable automatic double-puppeting via Shared Secret Auth (https://github.com/devture/matrix-synapse-shared-secret-auth).
 matrix_mx_puppet_discord_login_shared_secret: ''
 
+# Database configuration
+matrix_mx_puppet_discord_database_engine: 'sqlite'
+
+matrix_mx_puppet_discord_sqlite_database_path_local: "{{ matrix_mx_puppet_discord_data_path }}/database.db"
+matrix_mx_puppet_discord_sqlite_database_path_in_container: "/data/database.db"
+
+matrix_mx_puppet_discord_database_username: matrix_mx_puppet_discord
+matrix_mx_puppet_discord_database_password: ~
+matrix_mx_puppet_discord_database_hostname: 'matrix-postgres'
+matrix_mx_puppet_discord_database_port: 5432
+matrix_mx_puppet_discord_database_name: matrix_mx_puppet_discord
+
+matrix_mx_puppet_discord_database_connection_string: 'postgresql://{{ matrix_mx_puppet_discord_database_username }}:{{ matrix_mx_puppet_discord_database_password }}@{{ matrix_mx_puppet_discord_database_hostname }}:{{ matrix_mx_puppet_discord_database_port }}/{{ matrix_mx_puppet_discord_database_name }}?sslmode=disable'
+
 # Default configuration template which covers the generic use case.
 # You can customize it by controlling the various variables inside it.
 #
diff --git a/roles/matrix-bridge-mx-puppet-discord/tasks/setup_install.yml b/roles/matrix-bridge-mx-puppet-discord/tasks/setup_install.yml
index c3f2b01f..3e3b2f94 100644
--- a/roles/matrix-bridge-mx-puppet-discord/tasks/setup_install.yml
+++ b/roles/matrix-bridge-mx-puppet-discord/tasks/setup_install.yml
@@ -8,14 +8,6 @@
       The matrix-bridge-mx-puppet-discord role needs to execute before the matrix-synapse role.
   when: "matrix_synapse_role_executed|default(False)"
 
-- name: Ensure MX Puppet Discord image is pulled
-  docker_image:
-    name: "{{ matrix_mx_puppet_discord_docker_image }}"
-    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
-    force_source: "{{ matrix_mx_puppet_discord_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
-    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_mx_puppet_discord_docker_image_force_pull }}"
-  when: matrix_mx_puppet_discord_enabled|bool and not matrix_mx_puppet_discord_container_image_self_build
-
 - name: Ensure MX Puppet Discord paths exist
   file:
     path: "{{ item.path }}"
@@ -30,6 +22,57 @@
     - { path: "{{ matrix_mx_puppet_discord_docker_src_files_path }}", when: "{{ matrix_mx_puppet_discord_container_image_self_build }}" }
   when: matrix_mx_puppet_discord_enabled|bool and item.when|bool
 
+- name: Check if an old database file already exists
+  stat:
+    path: "{{ matrix_mx_puppet_discord_base_path }}/database.db"
+  register: matrix_mx_puppet_discord_stat_database
+
+- block:
+    - name: (Data relocation) Ensure matrix-mx-puppet-discord.service is stopped
+      service:
+        name: matrix-mx-puppet-discord
+        state: stopped
+        daemon_reload: yes
+      failed_when: False
+
+    - name: (Data relocation) Move mx-puppet-discord database file to ./data directory
+      command: "mv {{ matrix_mx_puppet_discord_base_path }}/database.db {{ matrix_mx_puppet_discord_data_path }}/database.db"
+  when: "matrix_mx_puppet_discord_stat_database.stat.exists"
+
+- set_fact:
+    matrix_mx_puppet_discord_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_mx_puppet_discord_sqlite_database_path_local }}"
+      register: matrix_mx_puppet_discord_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_mx_puppet_discord_sqlite_database_path_local }}"
+              dst: "{{ matrix_mx_puppet_discord_database_connection_string }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_mx_puppet_discord_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-mx-puppet-discord.service']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_mx_puppet_discord_requires_restart: true
+      when: "matrix_mx_puppet_discord_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_mx_puppet_discord_database_engine == 'postgres'"
+
+- name: Ensure MX Puppet Discord image is pulled
+  docker_image:
+    name: "{{ matrix_mx_puppet_discord_docker_image }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_mx_puppet_discord_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
+    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_mx_puppet_discord_docker_image_force_pull }}"
+  when: matrix_mx_puppet_discord_enabled|bool and not matrix_mx_puppet_discord_container_image_self_build
+
 - name: Ensure MX Puppet Discord repository is present on self build
   git:
     repo: "{{ matrix_mx_puppet_discord_container_image_self_build_repo }}"
@@ -49,23 +92,6 @@
       pull: yes
   when: "matrix_mx_puppet_discord_enabled|bool and matrix_mx_puppet_discord_container_image_self_build|bool"
 
-- name: Check if an old database file already exists
-  stat:
-    path: "{{ matrix_mx_puppet_discord_base_path }}/database.db"
-  register: matrix_mx_puppet_discord_stat_database
-
-- name: (Data relocation) Ensure matrix-mx-puppet-discord.service is stopped
-  service:
-    name: matrix-mx-puppet-discord
-    state: stopped
-    daemon_reload: yes
-  failed_when: false
-  when: "matrix_mx_puppet_discord_stat_database.stat.exists"
-
-- name: (Data relocation) Move mx-puppet-discord database file to ./data directory
-  command: "mv {{ matrix_mx_puppet_discord_base_path }}/database.db {{ matrix_mx_puppet_discord_data_path }}/database.db"
-  when: "matrix_mx_puppet_discord_stat_database.stat.exists"
-
 - name: Ensure mx-puppet-discord config.yaml installed
   copy:
     content: "{{ matrix_mx_puppet_discord_configuration|to_nice_yaml }}"
@@ -93,3 +119,9 @@
   service:
     daemon_reload: yes
   when: "matrix_mx_puppet_discord_systemd_service_result.changed"
+
+- name: Ensure matrix-mx-puppet-discord.service restarted, if necessary
+  service:
+    name: "matrix-mx-puppet-discord.service"
+    state: restarted
+  when: "matrix_mx_puppet_discord_requires_restart|bool"
diff --git a/roles/matrix-bridge-mx-puppet-discord/templates/config.yaml.j2 b/roles/matrix-bridge-mx-puppet-discord/templates/config.yaml.j2
index 2c703796..1f4548d8 100644
--- a/roles/matrix-bridge-mx-puppet-discord/templates/config.yaml.j2
+++ b/roles/matrix-bridge-mx-puppet-discord/templates/config.yaml.j2
@@ -100,15 +100,18 @@ namePatterns:
   group: :name
 
 database:
+{% if matrix_mx_puppet_discord_database_engine == 'sqlite' %}
+  # Use SQLite3 as a database backend
+  # The name of the database file
+  filename: {{ matrix_mx_puppet_discord_sqlite_database_path_in_container|to_json }}
+{% else %}
   # Use Postgres as a database backend
   # If set, will be used instead of SQLite3
   # Connection string to connect to the Postgres instance
   # with username "user", password "pass", host "localhost" and database name "dbname".
   # Modify each value as necessary
-  #connString: "postgres://user:pass@localhost/dbname?sslmode=disable"
-  # Use SQLite3 as a database backend
-  # The name of the database file
-  filename: /data/database.db
+  connString: {{ matrix_mx_puppet_discord_database_connection_string|to_json }}
+{% endif %}
 
 logging:
   # Log level of console output
diff --git a/roles/matrix-bridge-mx-puppet-instagram/defaults/main.yml b/roles/matrix-bridge-mx-puppet-instagram/defaults/main.yml
index 21cde53f..cd08c010 100644
--- a/roles/matrix-bridge-mx-puppet-instagram/defaults/main.yml
+++ b/roles/matrix-bridge-mx-puppet-instagram/defaults/main.yml
@@ -46,6 +46,19 @@ matrix_mx_puppet_instagram_homeserver_token: ''
 # Can be set to enable automatic double-puppeting via Shared Secret Auth (https://github.com/devture/matrix-synapse-shared-secret-auth).
 matrix_mx_puppet_instagram_login_shared_secret: ''
 
+matrix_mx_puppet_instagram_database_engine: sqlite
+
+matrix_mx_puppet_instagram_sqlite_database_path_local: "{{ matrix_mx_puppet_instagram_data_path }}/database.db"
+matrix_mx_puppet_instagram_sqlite_database_path_in_container: "/data/database.db"
+
+matrix_mx_puppet_instagram_database_username: matrix_mx_puppet_instagram
+matrix_mx_puppet_instagram_database_password: ~
+matrix_mx_puppet_instagram_database_hostname: 'matrix-postgres'
+matrix_mx_puppet_instagram_database_port: 5432
+matrix_mx_puppet_instagram_database_name: matrix_mx_puppet_instagram
+
+matrix_mx_puppet_instagram_database_connection_string: 'postgresql://{{ matrix_mx_puppet_instagram_database_username }}:{{ matrix_mx_puppet_instagram_database_password }}@{{ matrix_mx_puppet_instagram_database_hostname }}:{{ matrix_mx_puppet_instagram_database_port }}/{{ matrix_mx_puppet_instagram_database_name }}?sslmode=disable'
+
 # Default configuration template which covers the generic use case.
 # You can customize it by controlling the various variables inside it.
 #
diff --git a/roles/matrix-bridge-mx-puppet-instagram/tasks/setup_install.yml b/roles/matrix-bridge-mx-puppet-instagram/tasks/setup_install.yml
index 78bd78c1..76bbd629 100644
--- a/roles/matrix-bridge-mx-puppet-instagram/tasks/setup_install.yml
+++ b/roles/matrix-bridge-mx-puppet-instagram/tasks/setup_install.yml
@@ -8,6 +8,33 @@
       The matrix-bridge-mx-puppet-instagram role needs to execute before the matrix-synapse role.
   when: "matrix_synapse_role_executed|default(False)"
 
+
+- set_fact:
+    matrix_mx_puppet_instagram_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_mx_puppet_instagram_sqlite_database_path_local }}"
+      register: matrix_mx_puppet_instagram_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_mx_puppet_instagram_sqlite_database_path_local }}"
+              dst: "{{ matrix_mx_puppet_instagram_database_connection_string }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_mx_puppet_instagram_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-mx-puppet-instagram.service']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_mx_puppet_instagram_requires_restart: true
+      when: "matrix_mx_puppet_instagram_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_mx_puppet_instagram_database_engine == 'postgres'"
+
 - name: Ensure mx-puppet-instagram image is pulled
   docker_image:
     name: "{{ matrix_mx_puppet_instagram_docker_image }}"
@@ -77,4 +104,8 @@
     daemon_reload: yes
   when: "matrix_mx_puppet_instagram_systemd_service_result.changed"
 
-
+- name: Ensure matrix-mx-puppet-instagram.service restarted, if necessary
+  service:
+    name: "matrix-mx-puppet-instagram.service"
+    state: restarted
+  when: "matrix_mx_puppet_instagram_requires_restart|bool"
diff --git a/roles/matrix-bridge-mx-puppet-instagram/templates/config.yaml.j2 b/roles/matrix-bridge-mx-puppet-instagram/templates/config.yaml.j2
index 634fbaec..b830da2b 100644
--- a/roles/matrix-bridge-mx-puppet-instagram/templates/config.yaml.j2
+++ b/roles/matrix-bridge-mx-puppet-instagram/templates/config.yaml.j2
@@ -44,15 +44,18 @@ provisioning:
   apiPrefix: /_matrix/provision
 
 database:
+{% if matrix_mx_puppet_instagram_database_engine == 'postgres' %}
   # Use Postgres as a database backend
   # If set, will be used instead of SQLite3
   # Connection string to connect to the Postgres instance
   # with username "user", password "pass", host "localhost" and database name "dbname".
   # Modify each value as necessary
-  #connString: "postgres://user:pass@localhost/dbname?sslmode=disable"
+  connString: {{ matrix_mx_puppet_instagram_database_connection_string|to_json }}
+{% else %}
   # Use SQLite3 as a database backend
   # The name of the database file
-  filename: /data/database.db
+  filename: {{ matrix_mx_puppet_instagram_sqlite_database_path_in_container|to_json }}
+{% endif %}
 
 logging:
   # Log level of console output
diff --git a/roles/matrix-bridge-mx-puppet-skype/defaults/main.yml b/roles/matrix-bridge-mx-puppet-skype/defaults/main.yml
index 0c16a8ba..83cd3dc5 100644
--- a/roles/matrix-bridge-mx-puppet-skype/defaults/main.yml
+++ b/roles/matrix-bridge-mx-puppet-skype/defaults/main.yml
@@ -53,6 +53,20 @@ matrix_mx_puppet_skype_homeserver_token: ''
 # Can be set to enable automatic double-puppeting via Shared Secret Auth (https://github.com/devture/matrix-synapse-shared-secret-auth).
 matrix_mx_puppet_skype_login_shared_secret: ''
 
+# Database configuration, role default is `sqlite` but playbook default is `postgres`
+matrix_mx_puppet_skype_database_engine: sqlite
+
+matrix_mx_puppet_skype_sqlite_database_path_local: "{{ matrix_mx_puppet_skype_data_path }}/database.db"
+matrix_mx_puppet_skype_sqlite_database_path_in_container: "/data/database.db"
+
+matrix_mx_puppet_skype_database_username: matrix_mx_puppet_skype
+matrix_mx_puppet_skype_database_password: ~
+matrix_mx_puppet_skype_database_hostname: 'matrix-postgres'
+matrix_mx_puppet_skype_database_port: 5432
+matrix_mx_puppet_skype_database_name: matrix_mx_puppet_skype
+
+matrix_mx_puppet_skype_database_connection_string: 'postgresql://{{ matrix_mx_puppet_skype_database_username }}:{{ matrix_mx_puppet_skype_database_password }}@{{ matrix_mx_puppet_skype_database_hostname }}:{{ matrix_mx_puppet_skype_database_port }}/{{ matrix_mx_puppet_skype_database_name }}?sslmode=disable'
+
 # Default configuration template which covers the generic use case.
 # You can customize it by controlling the various variables inside it.
 #
diff --git a/roles/matrix-bridge-mx-puppet-skype/tasks/setup_install.yml b/roles/matrix-bridge-mx-puppet-skype/tasks/setup_install.yml
index fb5185ed..9289a793 100644
--- a/roles/matrix-bridge-mx-puppet-skype/tasks/setup_install.yml
+++ b/roles/matrix-bridge-mx-puppet-skype/tasks/setup_install.yml
@@ -8,14 +8,6 @@
       The matrix-bridge-mx-puppet-skype role needs to execute before the matrix-synapse role.
   when: "matrix_synapse_role_executed|default(False)"
 
-- name: Ensure MX Puppet Skype image is pulled
-  docker_image:
-    name: "{{ matrix_mx_puppet_skype_docker_image }}"
-    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
-    force_source: "{{ matrix_mx_puppet_skype_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
-    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_mx_puppet_skype_docker_image_force_pull }}"
-  when: matrix_mx_puppet_skype_enabled|bool and not matrix_mx_puppet_skype_container_image_self_build
-
 - name: Ensure MX Puppet Skype paths exist
   file:
     path: "{{ item.path }}"
@@ -30,6 +22,57 @@
     - { path: "{{ matrix_mx_puppet_skype_docker_src_files_path }}", when: "{{ matrix_mx_puppet_skype_container_image_self_build }}" }
   when: matrix_mx_puppet_skype_enabled|bool and item.when|bool
 
+- name: Check if an old database file already exists
+  stat:
+    path: "{{ matrix_mx_puppet_skype_base_path }}/database.db"
+  register: matrix_mx_puppet_skype_stat_database
+
+- name: (Data relocation) Ensure matrix-mx-puppet-skype.service is stopped
+  service:
+    name: matrix-mx-puppet-skype
+    state: stopped
+    daemon_reload: yes
+  failed_when: false
+  when: "matrix_mx_puppet_skype_stat_database.stat.exists"
+
+- name: (Data relocation) Move mx-puppet-skype database file to ./data directory
+  command: "mv {{ matrix_mx_puppet_skype_base_path }}/database.db {{ matrix_mx_puppet_skype_data_path }}/database.db"
+  when: "matrix_mx_puppet_skype_stat_database.stat.exists"
+
+- set_fact:
+    matrix_mx_puppet_skype_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_mx_puppet_skype_sqlite_database_path_local }}"
+      register: matrix_mx_puppet_skype_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_mx_puppet_skype_sqlite_database_path_local }}"
+              dst: "{{ matrix_mx_puppet_skype_database_connection_string }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_mx_puppet_skype_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-mx-puppet-skype.service']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_mx_puppet_skype_requires_restart: true
+      when: "matrix_mx_puppet_skype_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_mx_puppet_skype_database_engine == 'postgres'"
+
+- name: Ensure MX Puppet Skype image is pulled
+  docker_image:
+    name: "{{ matrix_mx_puppet_skype_docker_image }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_mx_puppet_skype_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
+    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_mx_puppet_skype_docker_image_force_pull }}"
+  when: matrix_mx_puppet_skype_enabled|bool and not matrix_mx_puppet_skype_container_image_self_build
+
 - name: Ensure MX Puppet Skype repository is present on self build
   git:
     repo: "{{ matrix_mx_puppet_skype_container_image_self_build_repo }}"
@@ -49,23 +92,6 @@
       pull: yes
   when: "matrix_mx_puppet_skype_enabled|bool and matrix_mx_puppet_skype_container_image_self_build|bool"
 
-- name: Check if an old database file already exists
-  stat:
-    path: "{{ matrix_mx_puppet_skype_base_path }}/database.db"
-  register: matrix_mx_puppet_skype_stat_database
-
-- name: (Data relocation) Ensure matrix-mx-puppet-skype.service is stopped
-  service:
-    name: matrix-mx-puppet-skype
-    state: stopped
-    daemon_reload: yes
-  failed_when: false
-  when: "matrix_mx_puppet_skype_stat_database.stat.exists"
-
-- name: (Data relocation) Move mx-puppet-skype database file to ./data directory
-  command: "mv {{ matrix_mx_puppet_skype_base_path }}/database.db {{ matrix_mx_puppet_skype_data_path }}/database.db"
-  when: "matrix_mx_puppet_skype_stat_database.stat.exists"
-
 - name: Ensure mx-puppet-skype config.yaml installed
   copy:
     content: "{{ matrix_mx_puppet_skype_configuration|to_nice_yaml }}"
@@ -93,3 +119,9 @@
   service:
     daemon_reload: yes
   when: "matrix_mx_puppet_skype_systemd_service_result.changed"
+
+- name: Ensure matrix-mx-puppet-skype.service restarted, if necessary
+  service:
+    name: "matrix-mx-puppet-skype.service"
+    state: restarted
+  when: "matrix_mx_puppet_skype_requires_restart|bool"
diff --git a/roles/matrix-bridge-mx-puppet-skype/templates/config.yaml.j2 b/roles/matrix-bridge-mx-puppet-skype/templates/config.yaml.j2
index c7b5c870..d41d3a23 100644
--- a/roles/matrix-bridge-mx-puppet-skype/templates/config.yaml.j2
+++ b/roles/matrix-bridge-mx-puppet-skype/templates/config.yaml.j2
@@ -68,15 +68,18 @@ logging:
       #  - Store
 
 database:
+{% if matrix_mx_puppet_skype_database_engine == 'postgres' %}
   # Use Postgres as a database backend
   # If set, will be used instead of SQLite3
   # Connection string to connect to the Postgres instance
   # with username "user", password "pass", host "localhost" and database name "dbname".
   # Modify each value as necessary
-  #connString: "postgres://user:pass@localhost/dbname?sslmode=disable"
+  connString: {{ matrix_mx_puppet_skype_database_connection_string|to_json }}
+{% else %}
   # Use SQLite3 as a database backend
   # The name of the database file
-  filename: /data/database.db
+  filename: {{ matrix_mx_puppet_skype_sqlite_database_path_in_container|to_json }}
+{% endif %}
 
 provisioning:
   # Regex of Matrix IDs allowed to use the puppet bridge
diff --git a/roles/matrix-bridge-mx-puppet-slack/defaults/main.yml b/roles/matrix-bridge-mx-puppet-slack/defaults/main.yml
index 96ab7833..70b98ece 100644
--- a/roles/matrix-bridge-mx-puppet-slack/defaults/main.yml
+++ b/roles/matrix-bridge-mx-puppet-slack/defaults/main.yml
@@ -57,6 +57,20 @@ matrix_mx_puppet_slack_homeserver_token: ''
 # Can be set to enable automatic double-puppeting via Shared Secret Auth (https://github.com/devture/matrix-synapse-shared-secret-auth).
 matrix_mx_puppet_slack_login_shared_secret: ''
 
+# Database configuration, role uses 'sqlite' per default but playbook sets up postgres by default
+matrix_mx_puppet_slack_database_engine: sqlite
+
+matrix_mx_puppet_slack_sqlite_database_path_local: "{{ matrix_mx_puppet_slack_data_path }}/database.db"
+matrix_mx_puppet_slack_sqlite_database_path_in_container: "/data/database.db"
+
+matrix_mx_puppet_slack_database_username: matrix_mx_puppet_slack
+matrix_mx_puppet_slack_database_password: ~
+matrix_mx_puppet_slack_database_hostname: 'matrix-postgres'
+matrix_mx_puppet_slack_database_port: 5432
+matrix_mx_puppet_slack_database_name: matrix_mx_puppet_slack
+
+matrix_mx_puppet_slack_database_connection_string: 'postgresql://{{ matrix_mx_puppet_slack_database_username }}:{{ matrix_mx_puppet_slack_database_password }}@{{ matrix_mx_puppet_slack_database_hostname }}:{{ matrix_mx_puppet_slack_database_port }}/{{ matrix_mx_puppet_slack_database_name }}?sslmode=disable'
+
 # Default configuration template which covers the generic use case.
 # You can customize it by controlling the various variables inside it.
 #
diff --git a/roles/matrix-bridge-mx-puppet-slack/tasks/setup_install.yml b/roles/matrix-bridge-mx-puppet-slack/tasks/setup_install.yml
index 2e45ecf6..5d68435c 100644
--- a/roles/matrix-bridge-mx-puppet-slack/tasks/setup_install.yml
+++ b/roles/matrix-bridge-mx-puppet-slack/tasks/setup_install.yml
@@ -8,14 +8,6 @@
       The matrix-bridge-mx-puppet-slack role needs to execute before the matrix-synapse role.
   when: "matrix_synapse_role_executed|default(False)"
 
-- name: Ensure MX Puppet Slack image is pulled
-  docker_image:
-    name: "{{ matrix_mx_puppet_slack_docker_image }}"
-    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
-    force_source: "{{ matrix_mx_puppet_slack_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
-    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_mx_puppet_slack_docker_image_force_pull }}"
-  when: matrix_mx_puppet_slack_enabled|bool and not matrix_mx_puppet_slack_container_image_self_build
-
 - name: Ensure MX Puppet Slack paths exist
   file:
     path: "{{ item.path }}"
@@ -30,6 +22,53 @@
     - { path: "{{ matrix_mx_puppet_slack_docker_src_files_path }}", when: "{{ matrix_mx_puppet_slack_container_image_self_build }}" }
   when: matrix_mx_puppet_slack_enabled|bool and item.when|bool
 
+- name: Check if an old database file already exists
+  stat:
+    path: "{{ matrix_mx_puppet_slack_base_path }}/database.db"
+  register: matrix_mx_puppet_slack_stat_database
+
+- name: (Data relocation) Ensure matrix-mx-puppet-slack.service is stopped
+  service:
+    name: matrix-mx-puppet-slack
+    state: stopped
+    daemon_reload: yes
+  failed_when: false
+  when: "matrix_mx_puppet_slack_stat_database.stat.exists"
+
+- set_fact:
+    matrix_mx_puppet_slack_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_mx_puppet_slack_sqlite_database_path_local }}"
+      register: matrix_mx_puppet_slack_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_mx_puppet_slack_sqlite_database_path_local }}"
+              dst: "{{ matrix_mx_puppet_slack_database_connection_string }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_mx_puppet_slack_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-mx-puppet-slack.service']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_mx_puppet_slack_requires_restart: true
+      when: "matrix_mx_puppet_slack_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_mx_puppet_slack_database_engine == 'postgres'"
+
+- name: Ensure MX Puppet Slack image is pulled
+  docker_image:
+    name: "{{ matrix_mx_puppet_slack_docker_image }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_mx_puppet_slack_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
+    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_mx_puppet_slack_docker_image_force_pull }}"
+  when: matrix_mx_puppet_slack_enabled|bool and not matrix_mx_puppet_slack_container_image_self_build
+
 - name: Ensure MX Puppet Slack repository is present on self build
   git:
     repo: "{{ matrix_mx_puppet_slack_container_image_self_build_repo }}"
@@ -49,19 +88,6 @@
       pull: yes
   when: "matrix_mx_puppet_slack_enabled|bool and matrix_mx_puppet_slack_container_image_self_build"
 
-- name: Check if an old database file already exists
-  stat:
-    path: "{{ matrix_mx_puppet_slack_base_path }}/database.db"
-  register: matrix_mx_puppet_slack_stat_database
-
-- name: (Data relocation) Ensure matrix-mx-puppet-slack.service is stopped
-  service:
-    name: matrix-mx-puppet-slack
-    state: stopped
-    daemon_reload: yes
-  failed_when: false
-  when: "matrix_mx_puppet_slack_stat_database.stat.exists"
-
 - name: (Data relocation) Move mx-puppet-slack database file to ./data directory
   command: "mv {{ matrix_mx_puppet_slack_base_path }}/database.db {{ matrix_mx_puppet_slack_data_path }}/database.db"
   when: "matrix_mx_puppet_slack_stat_database.stat.exists"
@@ -93,3 +119,9 @@
   service:
     daemon_reload: yes
   when: "matrix_mx_puppet_slack_systemd_service_result.changed"
+
+- name: Ensure matrix-mx-puppet-slack.service restarted, if necessary
+  service:
+    name: "matrix-mx-puppet-slack.service"
+    state: restarted
+  when: "matrix_mx_puppet_slack_requires_restart|bool"
diff --git a/roles/matrix-bridge-mx-puppet-slack/templates/config.yaml.j2 b/roles/matrix-bridge-mx-puppet-slack/templates/config.yaml.j2
index b6e88784..af6b5cb8 100644
--- a/roles/matrix-bridge-mx-puppet-slack/templates/config.yaml.j2
+++ b/roles/matrix-bridge-mx-puppet-slack/templates/config.yaml.j2
@@ -58,15 +58,18 @@ provisioning:
   apiPrefix: /_matrix/provision
 
 database:
+{% if matrix_mx_puppet_slack_database_engine == 'postgres' %}
   # Use Postgres as a database backend
   # If set, will be used instead of SQLite3
   # Connection string to connect to the Postgres instance
   # with username "user", password "pass", host "localhost" and database name "dbname".
   # Modify each value as necessary
-  #connString: "postgres://user:pass@localhost/dbname?sslmode=disable"
+  connString: {{ matrix_mx_puppet_slack_database_connection_string|to_json }}
+{% else %}
   # Use SQLite3 as a database backend
   # The name of the database file
-  filename: /data/database.db
+  filename: {{ matrix_mx_puppet_slack_sqlite_database_path_in_container|to_json }}
+{% endif %}
 
 logging:
   # Log level of console output
diff --git a/roles/matrix-bridge-mx-puppet-steam/defaults/main.yml b/roles/matrix-bridge-mx-puppet-steam/defaults/main.yml
index b5eb8473..15fa889f 100644
--- a/roles/matrix-bridge-mx-puppet-steam/defaults/main.yml
+++ b/roles/matrix-bridge-mx-puppet-steam/defaults/main.yml
@@ -55,6 +55,19 @@ matrix_mx_puppet_steam_homeserver_token: ''
 # Can be set to enable automatic double-puppeting via Shared Secret Auth (https://github.com/devture/matrix-synapse-shared-secret-auth).
 matrix_mx_puppet_steam_login_shared_secret: ''
 
+matrix_mx_puppet_steam_database_engine: sqlite
+
+matrix_mx_puppet_steam_sqlite_database_path_local: "{{ matrix_mx_puppet_steam_data_path }}/database.db"
+matrix_mx_puppet_steam_sqlite_database_path_in_container: "/data/database.db"
+
+matrix_mx_puppet_steam_database_username: matrix_mx_puppet_steam
+matrix_mx_puppet_steam_database_password: ~
+matrix_mx_puppet_steam_database_hostname: 'matrix-postgres'
+matrix_mx_puppet_steam_database_port: 5432
+matrix_mx_puppet_steam_database_name: matrix_mx_puppet_steam
+
+matrix_mx_puppet_steam_database_connection_string: 'postgresql://{{ matrix_mx_puppet_steam_database_username }}:{{ matrix_mx_puppet_steam_database_password }}@{{ matrix_mx_puppet_steam_database_hostname }}:{{ matrix_mx_puppet_steam_database_port }}/{{ matrix_mx_puppet_steam_database_name }}?sslmode=disable'
+
 # Default configuration template which covers the generic use case.
 # You can customize it by controlling the various variables inside it.
 #
diff --git a/roles/matrix-bridge-mx-puppet-steam/tasks/setup_install.yml b/roles/matrix-bridge-mx-puppet-steam/tasks/setup_install.yml
index 7b7f8211..71f6d889 100644
--- a/roles/matrix-bridge-mx-puppet-steam/tasks/setup_install.yml
+++ b/roles/matrix-bridge-mx-puppet-steam/tasks/setup_install.yml
@@ -8,14 +8,6 @@
       The matrix-bridge-mx-puppet-steam role needs to execute before the matrix-synapse role.
   when: "matrix_synapse_role_executed|default(False)"
 
-- name: Ensure MX Puppet Steam image is pulled
-  docker_image:
-    name: "{{ matrix_mx_puppet_steam_docker_image }}"
-    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
-    force_source: "{{ matrix_mx_puppet_steam_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
-    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_mx_puppet_steam_docker_image_force_pull }}"
-  when: matrix_mx_puppet_steam_enabled|bool and not matrix_mx_puppet_steam_container_image_self_build
-
 - name: Ensure MX Puppet Steam paths exist
   file:
     path: "{{ item.path }}"
@@ -30,6 +22,57 @@
     - { path: "{{ matrix_mx_puppet_steam_docker_src_files_path }}", when: "{{ matrix_mx_puppet_steam_container_image_self_build }}" }
   when: matrix_mx_puppet_steam_enabled|bool and item.when|bool
 
+- name: Check if an old database file already exists
+  stat:
+    path: "{{ matrix_mx_puppet_steam_base_path }}/database.db"
+  register: matrix_mx_puppet_steam_stat_database
+
+- name: (Data relocation) Ensure matrix-mx-puppet-steam.service is stopped
+  service:
+    name: matrix-mx-puppet-steam
+    state: stopped
+    daemon_reload: yes
+  failed_when: false
+  when: "matrix_mx_puppet_steam_stat_database.stat.exists"
+
+- name: (Data relocation) Move mx-puppet-steam database file to ./data directory
+  command: "mv {{ matrix_mx_puppet_steam_base_path }}/database.db {{ matrix_mx_puppet_steam_data_path }}/database.db"
+  when: "matrix_mx_puppet_steam_stat_database.stat.exists"
+
+- set_fact:
+    matrix_mx_puppet_steam_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_mx_puppet_steam_sqlite_database_path_local }}"
+      register: matrix_mx_puppet_steam_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_mx_puppet_steam_sqlite_database_path_local }}"
+              dst: "{{ matrix_mx_puppet_steam_database_connection_string }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_mx_puppet_steam_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-mx-puppet-steam.service']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_mx_puppet_steam_requires_restart: true
+      when: "matrix_mx_puppet_steam_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_mx_puppet_steam_database_engine == 'postgres'"
+
+- name: Ensure MX Puppet Steam image is pulled
+  docker_image:
+    name: "{{ matrix_mx_puppet_steam_docker_image }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_mx_puppet_steam_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
+    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_mx_puppet_steam_docker_image_force_pull }}"
+  when: matrix_mx_puppet_steam_enabled|bool and not matrix_mx_puppet_steam_container_image_self_build
+
 - name: Ensure MX Puppet Steam repository is present on self build
   git:
     repo: "{{ matrix_mx_puppet_steam_container_image_self_build_repo }}"
@@ -49,23 +92,6 @@
       pull: yes
   when: "matrix_mx_puppet_steam_enabled|bool and matrix_mx_puppet_steam_container_image_self_build"
 
-- name: Check if an old database file already exists
-  stat:
-    path: "{{ matrix_mx_puppet_steam_base_path }}/database.db"
-  register: matrix_mx_puppet_steam_stat_database
-
-- name: (Data relocation) Ensure matrix-mx-puppet-steam.service is stopped
-  service:
-    name: matrix-mx-puppet-steam
-    state: stopped
-    daemon_reload: yes
-  failed_when: false
-  when: "matrix_mx_puppet_steam_stat_database.stat.exists"
-
-- name: (Data relocation) Move mx-puppet-steam database file to ./data directory
-  command: "mv {{ matrix_mx_puppet_steam_base_path }}/database.db {{ matrix_mx_puppet_steam_data_path }}/database.db"
-  when: "matrix_mx_puppet_steam_stat_database.stat.exists"
-
 - name: Ensure mx-puppet-steam config.yaml installed
   copy:
     content: "{{ matrix_mx_puppet_steam_configuration|to_nice_yaml }}"
@@ -93,3 +119,9 @@
   service:
     daemon_reload: yes
   when: "matrix_mx_puppet_steam_systemd_service_result.changed"
+
+- name: Ensure matrix-mx-puppet-steam.service restarted, if necessary
+  service:
+    name: "matrix-mx-puppet-steam.service"
+    state: restarted
+  when: "matrix_mx_puppet_steam_requires_restart|bool"
diff --git a/roles/matrix-bridge-mx-puppet-steam/templates/config.yaml.j2 b/roles/matrix-bridge-mx-puppet-steam/templates/config.yaml.j2
index d08982ca..149e08b6 100644
--- a/roles/matrix-bridge-mx-puppet-steam/templates/config.yaml.j2
+++ b/roles/matrix-bridge-mx-puppet-steam/templates/config.yaml.j2
@@ -61,15 +61,18 @@ selfService:
   blacklist: {{ matrix_mx_puppet_steam_provisioning_blacklist|to_json }}
 
 database:
+{% if matrix_mx_puppet_steam_database_engine == 'postgres' %}
   # Use Postgres as a database backend
   # If set, will be used instead of SQLite3
   # Connection string to connect to the Postgres instance
   # with username "user", password "pass", host "localhost" and database name "dbname".
   # Modify each value as necessary
-  #connString: "postgres://user:pass@localhost/dbname?sslmode=disable"
+  connString: {{ matrix_mx_puppet_steam_database_connection_string|to_json }}
+{% else %}
   # Use SQLite3 as a database backend
   # The name of the database file
-  filename: /data/database.db
+  filename: {{ matrix_mx_puppet_steam_sqlite_database_path_in_container|to_json }}
+{% endif %}
 
 logging:
   # Log level of console output
diff --git a/roles/matrix-bridge-mx-puppet-twitter/defaults/main.yml b/roles/matrix-bridge-mx-puppet-twitter/defaults/main.yml
index 13438a21..28639fda 100644
--- a/roles/matrix-bridge-mx-puppet-twitter/defaults/main.yml
+++ b/roles/matrix-bridge-mx-puppet-twitter/defaults/main.yml
@@ -60,6 +60,20 @@ matrix_mx_puppet_twitter_homeserver_token: ''
 # Can be set to enable automatic double-puppeting via Shared Secret Auth (https://github.com/devture/matrix-synapse-shared-secret-auth).
 matrix_mx_puppet_twitter_login_shared_secret: ''
 
+# Database configuration
+matrix_mx_puppet_twitter_database_engine: sqlite
+
+matrix_mx_puppet_twitter_sqlite_database_path_local: "{{ matrix_mx_puppet_twitter_data_path }}/database.db"
+matrix_mx_puppet_twitter_sqlite_database_path_in_container: "/data/database.db"
+
+matrix_mx_puppet_twitter_database_username: mx_puppet_twitter
+matrix_mx_puppet_twitter_database_password: ~
+matrix_mx_puppet_twitter_database_hostname: 'matrix-postgres'
+matrix_mx_puppet_twitter_database_port: 5432
+matrix_mx_puppet_twitter_database_name: matrix_mx_puppet_twitter
+
+matrix_mx_puppet_twitter_database_connection_string: 'postgresql://{{ matrix_mx_puppet_twitter_database_username }}:{{ matrix_mx_puppet_twitter_database_password }}@{{ matrix_mx_puppet_twitter_database_hostname }}:{{ matrix_mx_puppet_twitter_database_port }}/{{ matrix_mx_puppet_twitter_database_name }}?sslmode=disable'
+
 # Default configuration template which covers the generic use case.
 # You can customize it by controlling the various variables inside it.
 #
diff --git a/roles/matrix-bridge-mx-puppet-twitter/tasks/setup_install.yml b/roles/matrix-bridge-mx-puppet-twitter/tasks/setup_install.yml
index 663f822c..3893981a 100644
--- a/roles/matrix-bridge-mx-puppet-twitter/tasks/setup_install.yml
+++ b/roles/matrix-bridge-mx-puppet-twitter/tasks/setup_install.yml
@@ -8,14 +8,6 @@
       The matrix-bridge-mx-puppet-twitter role needs to execute before the matrix-synapse role.
   when: "matrix_synapse_role_executed|default(False)"
 
-- name: Ensure MX Puppet Twitter image is pulled
-  docker_image:
-    name: "{{ matrix_mx_puppet_twitter_docker_image }}"
-    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
-    force_source: "{{ matrix_mx_puppet_twitter_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
-    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_mx_puppet_twitter_docker_image_force_pull }}"
-  when: matrix_mx_puppet_twitter_enabled|bool and not matrix_mx_puppet_twitter_container_image_self_build
-
 - name: Ensure MX Puppet Twitter paths exist
   file:
     path: "{{ item.path }}"
@@ -30,6 +22,57 @@
     - { path: "{{ matrix_mx_puppet_twitter_docker_src_files_path }}", when: "{{ matrix_mx_puppet_twitter_container_image_self_build }}" }
   when: matrix_mx_puppet_twitter_enabled|bool and item.when|bool
 
+- name: Check if an old database file already exists
+  stat:
+    path: "{{ matrix_mx_puppet_twitter_base_path }}/database.db"
+  register: matrix_mx_puppet_twitter_stat_database
+
+- name: (Data relocation) Ensure matrix-mx-puppet-twitter.service is stopped
+  service:
+    name: matrix-mx-puppet-twitter
+    state: stopped
+    daemon_reload: yes
+  failed_when: false
+  when: "matrix_mx_puppet_twitter_stat_database.stat.exists"
+
+- name: (Data relocation) Move mx-puppet-twitter database file to ./data directory
+  command: "mv {{ matrix_mx_puppet_twitter_base_path }}/database.db {{ matrix_mx_puppet_twitter_data_path }}/database.db"
+  when: "matrix_mx_puppet_twitter_stat_database.stat.exists"
+
+- set_fact:
+    matrix_mx_puppet_twitter_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_mx_puppet_twitter_sqlite_database_path_local }}"
+      register: matrix_mx_puppet_twitter_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_mx_puppet_twitter_sqlite_database_path_local }}"
+              dst: "{{ matrix_mx_puppet_twitter_database_connection_string }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_mx_puppet_twitter_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-mx-puppet-twitter.service']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_mx_puppet_twitter_requires_restart: true
+      when: "matrix_mx_puppet_twitter_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_mx_puppet_twitter_database_engine == 'postgres'"
+
+- name: Ensure MX Puppet Twitter image is pulled
+  docker_image:
+    name: "{{ matrix_mx_puppet_twitter_docker_image }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_mx_puppet_twitter_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
+    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_mx_puppet_twitter_docker_image_force_pull }}"
+  when: matrix_mx_puppet_twitter_enabled|bool and not matrix_mx_puppet_twitter_container_image_self_build
+
 - name: Ensure MX Puppet Twitter repository is present on self build
   git:
     repo: "{{ matrix_mx_puppet_twitter_container_image_self_build_repo }}"
@@ -49,23 +92,6 @@
       pull: yes
   when: "matrix_mx_puppet_twitter_enabled|bool and matrix_mx_puppet_twitter_container_image_self_build"
 
-- name: Check if an old database file already exists
-  stat:
-    path: "{{ matrix_mx_puppet_twitter_base_path }}/database.db"
-  register: matrix_mx_puppet_twitter_stat_database
-
-- name: (Data relocation) Ensure matrix-mx-puppet-twitter.service is stopped
-  service:
-    name: matrix-mx-puppet-twitter
-    state: stopped
-    daemon_reload: yes
-  failed_when: false
-  when: "matrix_mx_puppet_twitter_stat_database.stat.exists"
-
-- name: (Data relocation) Move mx-puppet-twitter database file to ./data directory
-  command: "mv {{ matrix_mx_puppet_twitter_base_path }}/database.db {{ matrix_mx_puppet_twitter_data_path }}/database.db"
-  when: "matrix_mx_puppet_twitter_stat_database.stat.exists"
-
 - name: Ensure mx-puppet-twitter config.yaml installed
   copy:
     content: "{{ matrix_mx_puppet_twitter_configuration|to_nice_yaml }}"
@@ -93,3 +119,9 @@
   service:
     daemon_reload: yes
   when: "matrix_mx_puppet_twitter_systemd_service_result.changed"
+
+- name: Ensure matrix-mx-puppet-twitter.service restarted, if necessary
+  service:
+    name: "matrix-mx-puppet-twitter.service"
+    state: restarted
+  when: "matrix_mx_puppet_twitter_requires_restart|bool"
diff --git a/roles/matrix-bridge-mx-puppet-twitter/templates/config.yaml.j2 b/roles/matrix-bridge-mx-puppet-twitter/templates/config.yaml.j2
index 7d3033b3..bdecf1dc 100644
--- a/roles/matrix-bridge-mx-puppet-twitter/templates/config.yaml.j2
+++ b/roles/matrix-bridge-mx-puppet-twitter/templates/config.yaml.j2
@@ -54,15 +54,18 @@ provisioning:
   apiPrefix: /_matrix/provision
 
 database:
+{% if matrix_mx_puppet_twitter_database_engine == 'postgres' %}
   # Use Postgres as a database backend
   # If set, will be used instead of SQLite3
   # Connection string to connect to the Postgres instance
   # with username "user", password "pass", host "localhost" and database name "dbname".
   # Modify each value as necessary
-  #connString: "postgres://user:pass@localhost/dbname?sslmode=disable"
+  connString: {{ matrix_mx_puppet_twitter_database_connection_string|to_json }}
+{% else %}
   # Use SQLite3 as a database backend
   # The name of the database file
-  filename: /data/database.db
+  filename: {{ matrix_mx_puppet_twitter_sqlite_database_path_in_container|to_json }}
+{% endif %}
 
 logging:
   # Log level of console output
diff --git a/roles/matrix-dimension/defaults/main.yml b/roles/matrix-dimension/defaults/main.yml
index 3b69227a..8a691946 100644
--- a/roles/matrix-dimension/defaults/main.yml
+++ b/roles/matrix-dimension/defaults/main.yml
@@ -15,6 +15,12 @@ matrix_dimension_base_path: "{{ matrix_base_data_path }}/dimension"
 matrix_dimension_docker_image: "docker.io/turt2live/matrix-dimension:latest"
 matrix_dimension_docker_image_force_pull: "{{ matrix_dimension_docker_image.endswith(':latest') }}"
 
+# List of systemd services that matrix-dimension.service depends on.
+matrix_dimension_systemd_required_services_list: ['docker.service']
+
+# List of systemd services that matrix-dimension.service wants
+matrix_dimension_systemd_wanted_services_list: []
+
 # The user and group id correspond to the node user in the `turt2live/matrix-dimension` image.
 matrix_dimension_user_uid: '1000'
 matrix_dimension_user_gid: '1000'
@@ -34,6 +40,28 @@ matrix_dimension_integrations_jitsi_widget_url: "https://{{ matrix_server_fqn_di
 
 matrix_dimension_homeserver_federationUrl: "http://matrix-synapse:8048"
 
+
+# Database-related configuration fields.
+#
+# To use SQLite, stick to these defaults.
+#
+# To use Postgres:
+# - change the engine (`matrix_dimension_database_engine: 'postgres'`)
+# - adjust your database credentials via the `matrix_dimension_postgres_*` variables
+matrix_dimension_database_engine: 'sqlite'
+
+matrix_dimension_sqlite_database_path_local: "{{ matrix_dimension_base_path }}/dimension.db"
+matrix_dimension_sqlite_database_path_in_container: "dimension.db"
+
+matrix_dimension_database_username: 'matrix_dimension'
+matrix_dimension_database_password: 'some-password'
+matrix_dimension_database_hostname: 'matrix-postgres'
+matrix_dimension_database_port: 5432
+matrix_dimension_database_name: 'matrix_dimension'
+
+matrix_dimension_database_connection_string: 'postgres://{{ matrix_dimension_database_username }}:{{ matrix_dimension_database_password }}@{{ matrix_dimension_database_hostname }}:{{ matrix_dimension_database_port }}/{{ matrix_dimension_database_name }}'
+
+
 # Default Dimension configuration template which covers the generic use case.
 # You can customize it by controlling the various variables inside it.
 #
diff --git a/roles/matrix-dimension/tasks/main.yml b/roles/matrix-dimension/tasks/main.yml
index 1888f945..aad55286 100644
--- a/roles/matrix-dimension/tasks/main.yml
+++ b/roles/matrix-dimension/tasks/main.yml
@@ -8,8 +8,14 @@
     - setup-all
     - setup-dimension
 
-- import_tasks: "{{ role_path }}/tasks/setup_dimension.yml"
-  when: run_setup|bool
+- import_tasks: "{{ role_path }}/tasks/setup_install.yml"
+  when: run_setup|bool and matrix_dimension_enabled|bool
+  tags:
+    - setup-all
+    - setup-dimension
+
+- import_tasks: "{{ role_path }}/tasks/setup_uninstall.yml"
+  when: run_setup|bool and not matrix_dimension_enabled|bool
   tags:
     - setup-all
     - setup-dimension
diff --git a/roles/matrix-dimension/tasks/setup_dimension.yml b/roles/matrix-dimension/tasks/setup_dimension.yml
deleted file mode 100644
index 2437a547..00000000
--- a/roles/matrix-dimension/tasks/setup_dimension.yml
+++ /dev/null
@@ -1,85 +0,0 @@
----
-
-#
-# Tasks related to setting up the dimension
-#
-
-- name: Ensure Dimension base path exists
-  file:
-    path: "{{ matrix_dimension_base_path }}"
-    state: directory
-    mode: 0770
-    owner: "{{ matrix_user_username }}"
-    group: "{{ matrix_dimension_user_gid }}"
-  when: matrix_dimension_enabled|bool
-
-- name: Ensure Dimension config installed
-  copy:
-    content: "{{ matrix_dimension_configuration|to_nice_yaml }}"
-    dest: "{{ matrix_dimension_base_path }}/config.yaml"
-    mode: 0640
-    owner: "{{ matrix_user_username }}"
-    group: "{{ matrix_dimension_user_gid }}"
-  when: matrix_dimension_enabled|bool
-
-- name: Ensure Dimension image is pulled
-  docker_image:
-    name: "{{ matrix_dimension_docker_image }}"
-    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
-    force_source: "{{ matrix_dimension_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
-    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_dimension_docker_image_force_pull }}"
-  when: matrix_dimension_enabled|bool
-
-- name: Ensure matrix-dimension.service installed
-  template:
-    src: "{{ role_path }}/templates/systemd/matrix-dimension.service.j2"
-    dest: "{{ matrix_systemd_path }}/matrix-dimension.service"
-    mode: 0644
-  register: matrix_dimension_systemd_service_result
-  when: matrix_dimension_enabled|bool
-
-- name: Ensure systemd reloaded after matrix-dimension.service installation
-  service:
-    daemon_reload: yes
-  when: "matrix_dimension_enabled|bool and matrix_dimension_systemd_service_result.changed"
-
-#
-# Tasks related to getting rid of the dimension (if it was previously enabled)
-#
-
-- name: Check existence of matrix-dimension service
-  stat:
-    path: "{{ matrix_systemd_path }}/matrix-dimension.service"
-  register: matrix_dimension_service_stat
-  when: "not matrix_dimension_enabled|bool"
-
-- name: Ensure matrix-dimension is stopped
-  service:
-    name: matrix-dimension
-    state: stopped
-    daemon_reload: yes
-  register: stopping_result
-  when: "not matrix_dimension_enabled|bool and matrix_dimension_service_stat.stat.exists"
-
-- name: Ensure matrix-dimension.service doesn't exist
-  file:
-    path: "{{ matrix_systemd_path }}/matrix-dimension.service"
-    state: absent
-  when: "not matrix_dimension_enabled|bool and matrix_dimension_service_stat.stat.exists"
-
-- name: Ensure systemd reloaded after matrix-dimension.service removal
-  service:
-    daemon_reload: yes
-  when: "not matrix_dimension_enabled|bool and matrix_dimension_service_stat.stat.exists"
-
-- name: Ensure Dimension environment variables path doesn't exist
-  file:
-    path: "{{ matrix_dimension_base_path }}"
-    state: absent
-  when: "not matrix_dimension_enabled|bool"
-
-- name: Ensure Dimension Docker image doesn't exist
-  docker_image:
-    name: "{{ matrix_dimension_docker_image }}"
-    state: absent
-  when: "not matrix_dimension_enabled|bool"
diff --git a/roles/matrix-dimension/tasks/setup_install.yml b/roles/matrix-dimension/tasks/setup_install.yml
new file mode 100644
index 00000000..9a264449
--- /dev/null
+++ b/roles/matrix-dimension/tasks/setup_install.yml
@@ -0,0 +1,69 @@
+---
+
+- set_fact:
+    matrix_dimension_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_dimension_sqlite_database_path_local }}"
+      register: matrix_dimension_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_dimension_sqlite_database_path_local }}"
+              dst: "{{ matrix_dimension_database_connection_string }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_dimension_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-dimension.service']
+              pgloader_options: ['--with "quote identifiers"']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_dimension_requires_restart: true
+      when: "matrix_dimension_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_dimension_database_engine == 'postgres'"
+
+- name: Ensure Dimension base path exists
+  file:
+    path: "{{ matrix_dimension_base_path }}"
+    state: directory
+    mode: 0770
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_dimension_user_gid }}"
+
+- name: Ensure Dimension config installed
+  copy:
+    content: "{{ matrix_dimension_configuration|to_nice_yaml }}"
+    dest: "{{ matrix_dimension_base_path }}/config.yaml"
+    mode: 0640
+    owner: "{{ matrix_user_username }}"
+    group: "{{ matrix_dimension_user_gid }}"
+
+- name: Ensure Dimension image is pulled
+  docker_image:
+    name: "{{ matrix_dimension_docker_image }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_dimension_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
+    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_dimension_docker_image_force_pull }}"
+
+- name: Ensure matrix-dimension.service installed
+  template:
+    src: "{{ role_path }}/templates/systemd/matrix-dimension.service.j2"
+    dest: "{{ matrix_systemd_path }}/matrix-dimension.service"
+    mode: 0644
+  register: matrix_dimension_systemd_service_result
+
+- name: Ensure systemd reloaded after matrix-dimension.service installation
+  service:
+    daemon_reload: yes
+  when: "matrix_dimension_systemd_service_result.changed|bool"
+
+- name: Ensure matrix-dimension.service restarted, if necessary
+  service:
+    name: "matrix-dimension.service"
+    state: restarted
+  when: "matrix_dimension_requires_restart|bool"
diff --git a/roles/matrix-dimension/tasks/setup_uninstall.yml b/roles/matrix-dimension/tasks/setup_uninstall.yml
new file mode 100644
index 00000000..9bc4ac8b
--- /dev/null
+++ b/roles/matrix-dimension/tasks/setup_uninstall.yml
@@ -0,0 +1,35 @@
+---
+
+- name: Check existence of matrix-dimension service
+  stat:
+    path: "{{ matrix_systemd_path }}/matrix-dimension.service"
+  register: matrix_dimension_service_stat
+
+- name: Ensure matrix-dimension is stopped
+  service:
+    name: matrix-dimension
+    state: stopped
+    daemon_reload: yes
+  register: stopping_result
+  when: "matrix_dimension_service_stat.stat.exists|bool"
+
+- name: Ensure matrix-dimension.service doesn't exist
+  file:
+    path: "{{ matrix_systemd_path }}/matrix-dimension.service"
+    state: absent
+  when: "matrix_dimension_service_stat.stat.exists|bool"
+
+- name: Ensure systemd reloaded after matrix-dimension.service removal
+  service:
+    daemon_reload: yes
+  when: "matrix_dimension_service_stat.stat.exists|bool"
+
+- name: Ensure Dimension base directory doesn't exist
+  file:
+    path: "{{ matrix_dimension_base_path }}"
+    state: absent
+
+- name: Ensure Dimension Docker image doesn't exist
+  docker_image:
+    name: "{{ matrix_dimension_docker_image }}"
+    state: absent
diff --git a/roles/matrix-dimension/templates/config.yaml.j2 b/roles/matrix-dimension/templates/config.yaml.j2
index a05b6c35..200871e7 100644
--- a/roles/matrix-dimension/templates/config.yaml.j2
+++ b/roles/matrix-dimension/templates/config.yaml.j2
@@ -44,7 +44,11 @@ widgetBlacklist:
 
 # Where the database for Dimension is
 database:
-  file: "dimension.db"
+{% if matrix_dimension_database_engine == 'sqlite' %}
+  file: {{ matrix_dimension_sqlite_database_path_in_container|to_json }}
+{% elif matrix_dimension_database_engine == 'postgres' %}
+  uri: {{ matrix_dimension_database_connection_string|to_json }}
+{% endif %}
 
 # Display settings that apply to self-hosted go-neb instances
 goneb:
diff --git a/roles/matrix-dimension/templates/systemd/matrix-dimension.service.j2 b/roles/matrix-dimension/templates/systemd/matrix-dimension.service.j2
index 94c38491..ff10224a 100644
--- a/roles/matrix-dimension/templates/systemd/matrix-dimension.service.j2
+++ b/roles/matrix-dimension/templates/systemd/matrix-dimension.service.j2
@@ -1,8 +1,13 @@
 #jinja2: lstrip_blocks: "True"
 [Unit]
 Description=Matrix Dimension
-After=docker.service
-Requires=docker.service
+{% for service in matrix_dimension_systemd_required_services_list %}
+Requires={{ service }}
+After={{ service }}
+{% endfor %}
+{% for service in matrix_dimension_systemd_wanted_services_list %}
+Wants={{ service }}
+{% endfor %}
 DefaultDependencies=no
 
 [Service]
@@ -11,7 +16,9 @@ ExecStartPre=-{{ matrix_host_command_docker }} kill matrix-dimension
 ExecStartPre=-{{ matrix_host_command_docker }} rm matrix-dimension
 
 # Fixup database ownership if it got changed somehow (during a server migration, etc.)
-ExecStartPre=-{{ matrix_host_command_chown }} {{ matrix_dimension_user_uid }}:{{ matrix_dimension_user_gid }} {{ matrix_dimension_base_path }}/dimension.db
+{% if matrix_dimension_database_engine == 'sqlite' %}
+ExecStartPre=-{{ matrix_host_command_chown }} {{ matrix_dimension_user_uid }}:{{ matrix_dimension_user_gid }} {{ matrix_dimension_sqlite_database_path_local }}
+{% endif %}
 
 ExecStart={{ matrix_host_command_docker }} run --rm --name matrix-dimension \
 			--log-driver=none \
diff --git a/roles/matrix-ma1sd/defaults/main.yml b/roles/matrix-ma1sd/defaults/main.yml
index f7a0782d..2932f3ed 100644
--- a/roles/matrix-ma1sd/defaults/main.yml
+++ b/roles/matrix-ma1sd/defaults/main.yml
@@ -39,6 +39,28 @@ matrix_ma1sd_systemd_wanted_services_list: []
 # Enabling this is discouraged. Learn more here: https://github.com/ma1uta/ma1sd/blob/master/docs/features/identity.md#lookups
 matrix_ma1sd_matrixorg_forwarding_enabled: false
 
+
+# Database-related configuration fields.
+#
+# To use SQLite, stick to these defaults.
+#
+# To use Postgres:
+# - change the engine (`matrix_ma1sd_database_engine: 'postgres'`)
+# - adjust your database credentials via the `matrix_ma1sd_postgres_*` variables
+matrix_ma1sd_database_engine: 'sqlite'
+
+matrix_ma1sd_sqlite_database_path_local: "{{ matrix_ma1sd_data_path }}/ma1sd.db"
+matrix_ma1sd_sqlite_database_path_in_container: "/var/ma1sd/ma1sd.db"
+
+matrix_ma1sd_database_username: 'matrix_ma1sd'
+matrix_ma1sd_database_password: 'some-password'
+matrix_ma1sd_database_hostname: 'matrix-postgres'
+matrix_ma1sd_database_port: 5432
+matrix_ma1sd_database_name: 'matrix_ma1sd'
+
+matrix_ma1sd_database_connection_string: 'postgresql://{{ matrix_ma1sd_database_username }}:{{ matrix_ma1sd_database_password }}@{{ matrix_ma1sd_database_hostname }}:{{ matrix_ma1sd_database_port }}/{{ matrix_ma1sd_database_name }}'
+
+
 # ma1sd has serveral supported identity stores.
 # One of them is storing identities directly in Synapse's database.
 # Learn more here: https://github.com/ma1uta/ma1sd/blob/master/docs/stores/synapse.md
diff --git a/roles/matrix-ma1sd/tasks/main.yml b/roles/matrix-ma1sd/tasks/main.yml
index f5ac34d6..0b8a114e 100644
--- a/roles/matrix-ma1sd/tasks/main.yml
+++ b/roles/matrix-ma1sd/tasks/main.yml
@@ -8,7 +8,14 @@
     - setup-all
     - setup-ma1sd
 
-- import_tasks: "{{ role_path }}/tasks/setup_ma1sd.yml"
+- import_tasks: "{{ role_path }}/tasks/setup_install.yml"
+  when: "run_setup|bool and matrix_ma1sd_enabled|bool"
+  tags:
+    - setup-all
+    - setup-ma1sd
+
+- import_tasks: "{{ role_path }}/tasks/setup_uninstall.yml"
+  when: "run_setup|bool and not matrix_ma1sd_enabled|bool"
   tags:
     - setup-all
     - setup-ma1sd
diff --git a/roles/matrix-ma1sd/tasks/setup_ma1sd.yml b/roles/matrix-ma1sd/tasks/setup_install.yml
similarity index 69%
rename from roles/matrix-ma1sd/tasks/setup_ma1sd.yml
rename to roles/matrix-ma1sd/tasks/setup_install.yml
index 46acb428..9ae5f077 100644
--- a/roles/matrix-ma1sd/tasks/setup_ma1sd.yml
+++ b/roles/matrix-ma1sd/tasks/setup_install.yml
@@ -1,9 +1,5 @@
 ---
 
-#
-# Tasks related to setting up ma1sd
-#
-
 - name: Ensure ma1sd paths exist
   file:
     path: "{{ item.path }}"
@@ -15,10 +11,39 @@
     - { path: "{{ matrix_ma1sd_config_path }}", when: true }
     - { path: "{{ matrix_ma1sd_data_path }}", when: true }
     - { path: "{{ matrix_ma1sd_docker_src_files_path }}", when: "{{ matrix_ma1sd_container_image_self_build }}"}
-  when: matrix_ma1sd_enabled|bool and item.when
+  when: "item.when|bool"
 
 - import_tasks: "{{ role_path }}/tasks/migrate_mxisd.yml"
-  when: matrix_ma1sd_enabled|bool
+
+
+# These (SQLite -> Postgres) migration tasks are usually at the top,
+# but we'd like to run them after `migrate_mxisd.yml`, which requires the ma1sd paths to exist.
+- set_fact:
+    matrix_ma1sd_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_ma1sd_sqlite_database_path_local }}"
+      register: matrix_ma1sd_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_ma1sd_sqlite_database_path_local }}"
+              dst: "{{ matrix_ma1sd_database_connection_string }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_ma1sd_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-ma1sd.service']
+              pgloader_options: ['--with "quote identifiers"']
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_ma1sd_requires_restart: true
+      when: "matrix_ma1sd_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_ma1sd_database_engine == 'postgres'"
 
 - name: Ensure ma1sd image is pulled
   docker_image:
@@ -26,7 +51,7 @@
     source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
     force_source: "{{ matrix_ma1sd_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
     force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_ma1sd_docker_image_force_pull }}"
-  when: matrix_ma1sd_enabled|bool and not matrix_ma1sd_container_image_self_build
+  when: "not matrix_ma1sd_container_image_self_build|bool"
 
 - block:
   - name: Ensure gradle is installed for self-building (Debian)
@@ -72,7 +97,7 @@
       repository: "{{ matrix_ma1sd_docker_image }}"
       force_tag: yes
       source: local
-  when: "matrix_ma1sd_enabled|bool and matrix_ma1sd_container_image_self_build"
+  when: "matrix_ma1sd_container_image_self_build|bool"
 
 - name: Ensure ma1sd config installed
   copy:
@@ -81,7 +106,6 @@
     mode: 0644
     owner: "{{ matrix_user_username }}"
     group: "{{ matrix_user_groupname }}"
-  when: matrix_ma1sd_enabled|bool
 
 - name: Ensure custom templates are installed if any
   copy:
@@ -95,7 +119,7 @@
     - {value: "{{ matrix_ma1sd_threepid_medium_email_custom_session_validation_template }}", location: 'validate-template.eml'}
     - {value: "{{ matrix_ma1sd_threepid_medium_email_custom_unbind_fraudulent_template }}", location: 'unbind-fraudulent.eml'}
     - {value: "{{ matrix_ma1sd_threepid_medium_email_custom_matrixid_template }}", location: 'mxid-template.eml'}
-  when: "matrix_ma1sd_enabled|bool and matrix_ma1sd_threepid_medium_email_custom_templates_enabled|bool and item.value"
+  when: "matrix_ma1sd_threepid_medium_email_custom_templates_enabled|bool and item.value"
 
 - name: Ensure matrix-ma1sd.service installed
   template:
@@ -103,49 +127,14 @@
     dest: "{{ matrix_systemd_path }}/matrix-ma1sd.service"
     mode: 0644
   register: matrix_ma1sd_systemd_service_result
-  when: matrix_ma1sd_enabled|bool
 
 - name: Ensure systemd reloaded after matrix-ma1sd.service installation
   service:
     daemon_reload: yes
-  when: "matrix_ma1sd_enabled|bool and matrix_ma1sd_systemd_service_result.changed"
-
-#
-# Tasks related to getting rid of ma1sd (if it was previously enabled)
-#
-
-- name: Check existence of matrix-ma1sd service
-  stat:
-    path: "{{ matrix_systemd_path }}/matrix-ma1sd.service"
-  register: matrix_ma1sd_service_stat
-
-- name: Ensure matrix-ma1sd is stopped
-  service:
-    name: matrix-ma1sd
-    state: stopped
-    daemon_reload: yes
-  register: stopping_result
-  when: "not matrix_ma1sd_enabled|bool and matrix_ma1sd_service_stat.stat.exists"
-
-- name: Ensure matrix-ma1sd.service doesn't exist
-  file:
-    path: "{{ matrix_systemd_path }}/matrix-ma1sd.service"
-    state: absent
-  when: "not matrix_ma1sd_enabled|bool and matrix_ma1sd_service_stat.stat.exists"
+  when: "matrix_ma1sd_systemd_service_result.changed|bool"
 
-- name: Ensure systemd reloaded after matrix-ma1sd.service removal
+- name: Ensure matrix-ma1sd.service restarted, if necessary
   service:
-    daemon_reload: yes
-  when: "not matrix_ma1sd_enabled|bool and matrix_ma1sd_service_stat.stat.exists"
-
-- name: Ensure Matrix ma1sd paths don't exist
-  file:
-    path: "{{ matrix_ma1sd_base_path }}"
-    state: absent
-  when: "not matrix_ma1sd_enabled|bool"
-
-- name: Ensure ma1sd Docker image doesn't exist
-  docker_image:
-    name: "{{ matrix_ma1sd_docker_image }}"
-    state: absent
-  when: "not matrix_ma1sd_enabled|bool"
+    name: "matrix-ma1sd.service"
+    state: restarted
+  when: "matrix_ma1sd_requires_restart|bool"
diff --git a/roles/matrix-ma1sd/tasks/setup_uninstall.yml b/roles/matrix-ma1sd/tasks/setup_uninstall.yml
new file mode 100644
index 00000000..b36ab508
--- /dev/null
+++ b/roles/matrix-ma1sd/tasks/setup_uninstall.yml
@@ -0,0 +1,35 @@
+---
+
+- name: Check existence of matrix-ma1sd service
+  stat:
+    path: "{{ matrix_systemd_path }}/matrix-ma1sd.service"
+  register: matrix_ma1sd_service_stat
+
+- name: Ensure matrix-ma1sd is stopped
+  service:
+    name: matrix-ma1sd
+    state: stopped
+    daemon_reload: yes
+  register: stopping_result
+  when: "matrix_ma1sd_service_stat.stat.exists|bool"
+
+- name: Ensure matrix-ma1sd.service doesn't exist
+  file:
+    path: "{{ matrix_systemd_path }}/matrix-ma1sd.service"
+    state: absent
+  when: "matrix_ma1sd_service_stat.stat.exists|bool"
+
+- name: Ensure systemd reloaded after matrix-ma1sd.service removal
+  service:
+    daemon_reload: yes
+  when: "matrix_ma1sd_service_stat.stat.exists|bool"
+
+- name: Ensure Matrix ma1sd paths don't exist
+  file:
+    path: "{{ matrix_ma1sd_base_path }}"
+    state: absent
+
+- name: Ensure ma1sd Docker image doesn't exist
+  docker_image:
+    name: "{{ matrix_ma1sd_docker_image }}"
+    state: absent
diff --git a/roles/matrix-ma1sd/templates/ma1sd.yaml.j2 b/roles/matrix-ma1sd/templates/ma1sd.yaml.j2
index 84585707..9a426c47 100644
--- a/roles/matrix-ma1sd/templates/ma1sd.yaml.j2
+++ b/roles/matrix-ma1sd/templates/ma1sd.yaml.j2
@@ -11,9 +11,19 @@ key:
   path: /var/ma1sd/sign.key
 
 storage:
-  provider:
-    sqlite:
-      database: /var/ma1sd/ma1sd.db
+  {% if matrix_ma1sd_database_engine == 'sqlite' %}
+    backend: sqlite
+    provider:
+      sqlite:
+        database: {{ matrix_ma1sd_sqlite_database_path_in_container|to_json }}
+  {% elif matrix_ma1sd_database_engine == 'postgres' %}
+    backend: postgresql
+    provider:
+      postgresql:
+        database: //{{ matrix_ma1sd_database_hostname }}:{{ matrix_ma1sd_database_port }}/{{ matrix_ma1sd_database_name }}
+        username: {{ matrix_ma1sd_database_username|to_json }}
+        password: {{ matrix_ma1sd_database_password|to_json }}
+  {% endif %}
 
 {% if matrix_ma1sd_dns_overwrite_enabled %}
 dns:
diff --git a/roles/matrix-postgres/defaults/main.yml b/roles/matrix-postgres/defaults/main.yml
index ec5cb3dc..8f1d0d78 100644
--- a/roles/matrix-postgres/defaults/main.yml
+++ b/roles/matrix-postgres/defaults/main.yml
@@ -30,3 +30,50 @@ matrix_postgres_container_extra_arguments: []
 #
 # Takes an "<ip>:<port>" or "<port>" value (e.g. "127.0.0.1:5432"), or empty string to not expose.
 matrix_postgres_container_postgres_bind_port: ""
+
+# A list of additional (databases and their credentials) to create.
+#
+# Example:
+# matrix_postgres_additional_databases:
+#   - name: matrix_appservice_discord
+#     username: matrix_appservice_discord
+#     password: some_password
+#   - name: matrix_appservice_slack
+#     username: matrix_appservice_slack
+#     password: some_password
+matrix_postgres_additional_databases: []
+
+# A list of roles/users to avoid creating when importing (or upgrading) the database.
+# If a dump file contains the roles and they've also been created beforehand (see `matrix_postgres_additional_databases`),
+# importing would fail.
+# We either need to not create them or to ignore the `CREATE ROLE` statements in the dump.
+matrix_postgres_import_roles_to_ignore: [matrix_postgres_connection_username]
+
+matrix_postgres_import_roles_ignore_regex: "^CREATE ROLE ({{ matrix_postgres_import_roles_to_ignore|join('|') }});"
+
+# A list of databases to avoid creating when importing (or upgrading) the database.
+# If a dump file contains the databases and they've also been created beforehand (see `matrix_postgres_additional_databases`),
+# importing would fail.
+# We either need to not create them or to ignore the `CREATE DATABASE` statements in the dump.
+matrix_postgres_import_databases_to_ignore: [matrix_postgres_db_name]
+
+matrix_postgres_import_databases_ignore_regex: "^CREATE DATABASE ({{ matrix_postgres_import_databases_to_ignore|join('|') }})\\s"
+
+# The number of seconds to wait after starting `matrix-postgres.service`
+# and before trying to run queries for creating additional databases/users against it.
+#
+# For most (subsequent) runs, Postgres would already be running, so no waiting will be happening at all.
+matrix_postgres_additional_databases_postgres_start_wait_timeout_seconds: 15
+
+
+matrix_postgres_pgloader_container_image_self_build: false
+matrix_postgres_pgloader_container_image_self_build_repo: "https://github.com/illagrenan/pgloader-docker.git"
+matrix_postgres_pgloader_container_image_self_build_repo_branch: "v{{ matrix_postgres_pgloader_docker_image_tag }}"
+matrix_postgres_pgloader_container_image_self_build_src_path: "{{ matrix_postgres_base_path }}/pgloader-container-src"
+
+# We use illagrenan/pgloader, instead of the more official dimitri/pgloader image,
+# because the official one only provides a `latest` tag.
+matrix_postgres_pgloader_docker_image: "{{ matrix_postgres_pgloader_docker_image_name_prefix }}illagrenan/pgloader:{{ matrix_postgres_pgloader_docker_image_tag }}"
+matrix_postgres_pgloader_docker_image_name_prefix: "{{ 'localhost/' if matrix_postgres_pgloader_container_image_self_build else 'docker.io/' }}"
+matrix_postgres_pgloader_docker_image_tag: "3.6.2"
+matrix_postgres_pgloader_docker_image_force_pull: "{{ matrix_postgres_pgloader_docker_image.endswith(':latest') }}"
diff --git a/roles/matrix-postgres/tasks/import_generic_sqlite_db.yml b/roles/matrix-postgres/tasks/import_generic_sqlite_db.yml
new file mode 100644
index 00000000..a42c6f55
--- /dev/null
+++ b/roles/matrix-postgres/tasks/import_generic_sqlite_db.yml
@@ -0,0 +1,97 @@
+---
+
+# Pre-checks
+
+- name: Fail if Postgres not enabled
+  fail:
+    msg: "Postgres via the matrix-postgres role is not enabled (`matrix_postgres_enabled`). Cannot import."
+  when: "not matrix_postgres_enabled|bool"
+
+- name: Fail if playbook called incorrectly
+  fail:
+    msg: "The `sqlite_database_path` variable needs to be provided to this playbook, via --extra-vars"
+  when: "sqlite_database_path is not defined or sqlite_database_path.startswith('<')"
+
+- name: Check if the provided SQLite database file exists
+  stat:
+    path: "{{ sqlite_database_path }}"
+  register: sqlite_database_path_stat_result
+
+- name: Fail if provided SQLite database file doesn't exist
+  fail:
+    msg: "File cannot be found on the server at {{ sqlite_database_path }}"
+  when: "not sqlite_database_path_stat_result.stat.exists"
+
+# We either expect `postgres_db_connection_string` specifying a full Postgres database connection string,
+# or `postgres_connection_string_variable_name`, specifying a name of a variable, which contains a valid connection string.
+
+- block:
+    - name: Fail if postgres_connection_string_variable_name points to an undefined variable
+      fail: msg="postgres_connection_string_variable_name is defined, but there is no variable with the name `{{ postgres_connection_string_variable_name }}`"
+      when: "postgres_connection_string_variable_name not in vars"
+
+    - name: Get Postgres connection string from variable
+      set_fact:
+        postgres_db_connection_string: "{{ lookup('vars', postgres_connection_string_variable_name) }}"
+  when: 'postgres_connection_string_variable_name is defined'
+
+- name: Fail if playbook called incorrectly
+  fail:
+    msg: >-
+      Either a `postgres_db_connection_string` variable or a `postgres_connection_string_variable_name` needs to be provided to this playbook, via `--extra-vars`.
+      Example: `--extra-vars="postgres_db_connection_string=postgresql://username:password@localhost:<port>/database_name"` or `--extra-vars="postgres_connection_string_variable_name=matrix_appservice_discord_database_connString"`
+  when: "postgres_db_connection_string is not defined or not postgres_db_connection_string.startswith('postgresql://')"
+
+
+# Defaults
+
+- name: Set postgres_start_wait_time, if not provided
+  set_fact:
+    postgres_start_wait_time: 15
+  when: "postgres_start_wait_time|default('') == ''"
+
+
+# Actual import work
+
+- name: Ensure matrix-postgres is started
+  service:
+    name: matrix-postgres
+    state: started
+    daemon_reload: yes
+  register: matrix_postgres_service_start_result
+
+- name: Wait a bit, so that Postgres can start
+  wait_for:
+    timeout: "{{ postgres_start_wait_time }}"
+  delegate_to: 127.0.0.1
+  become: false
+  when: "matrix_postgres_service_start_result.changed|bool"
+
+- name: Import SQLite database from {{ sqlite_database_path }} into Postgres
+  command:
+    cmd: >-
+      {{ matrix_host_command_docker }} run
+      --rm
+      --user={{ matrix_user_uid }}:{{ matrix_user_gid }}
+      --cap-drop=ALL
+      --network={{ matrix_docker_network }}
+      --mount type=bind,src={{ sqlite_database_path }},dst=/in.db,ro
+      --entrypoint=/bin/sh
+      {{ matrix_postgres_pgloader_docker_image }}
+      -c
+      'pgloader /in.db {{ postgres_db_connection_string }}'
+
+- name: Archive SQLite database ({{ sqlite_database_path }} -> {{ sqlite_database_path }}.backup)
+  command:
+    cmd: "mv {{ sqlite_database_path }} {{ sqlite_database_path }}.backup"
+
+- name: Inject result
+  set_fact:
+    matrix_playbook_runtime_results: |
+      {{
+        matrix_playbook_runtime_results|default([])
+        +
+        [
+          "NOTE: Your SQLite database file has been imported into Postgres. The original file has been moved from `{{ sqlite_database_path }}` to `{{ sqlite_database_path }}.backup`. When you've confirmed that the import went well and everything works, you should be able to safely delete this file."
+        ]
+      }}
diff --git a/roles/matrix-postgres/tasks/import_postgres.yml b/roles/matrix-postgres/tasks/import_postgres.yml
index 33d98691..c26affbb 100644
--- a/roles/matrix-postgres/tasks/import_postgres.yml
+++ b/roles/matrix-postgres/tasks/import_postgres.yml
@@ -74,8 +74,8 @@
       {{ matrix_postgres_docker_image_latest }}
       -c "cat /{{ server_path_postgres_dump|basename }} |
       {{ 'gunzip |' if server_path_postgres_dump.endswith('.gz') else '' }}
-      grep -vE '^CREATE ROLE {{ matrix_postgres_connection_username }}' |
-      grep -vE '^CREATE DATABASE {{ matrix_postgres_db_name }}' |
+      grep -vE '{{ matrix_postgres_import_roles_ignore_regex }}' |
+      grep -vE '{{ matrix_postgres_import_databases_ignore_regex }}' |
       psql -v ON_ERROR_STOP=1 -h matrix-postgres"
 
 # This is a hack.
diff --git a/roles/matrix-postgres/tasks/main.yml b/roles/matrix-postgres/tasks/main.yml
index f4c752a0..b9c2ae7c 100644
--- a/roles/matrix-postgres/tasks/main.yml
+++ b/roles/matrix-postgres/tasks/main.yml
@@ -26,6 +26,12 @@
   tags:
     - import-synapse-sqlite-db
 
+# Perhaps we need a new variable here, instead of `run_postgres_import_sqlite_db`.
+- import_tasks: "{{ role_path }}/tasks/import_generic_sqlite_db.yml"
+  when: run_postgres_import_sqlite_db|bool
+  tags:
+    - import-generic-sqlite-db
+
 - import_tasks: "{{ role_path }}/tasks/upgrade_postgres.yml"
   when: run_postgres_upgrade|bool
   tags:
diff --git a/roles/matrix-postgres/tasks/setup_postgres.yml b/roles/matrix-postgres/tasks/setup_postgres.yml
index f186bdca..518d1a5f 100644
--- a/roles/matrix-postgres/tasks/setup_postgres.yml
+++ b/roles/matrix-postgres/tasks/setup_postgres.yml
@@ -113,6 +113,13 @@
     daemon_reload: yes
   when: "matrix_postgres_enabled|bool and matrix_postgres_systemd_service_result.changed"
 
+- include_tasks:
+    file: "{{ role_path }}/tasks/util/create_additional_databases.yml"
+    apply:
+      tags:
+        - always
+  when: "matrix_postgres_enabled|bool and matrix_postgres_additional_databases|length > 0"
+
 #
 # Tasks related to getting rid of the internal postgres server (if it was previously enabled)
 #
diff --git a/roles/matrix-postgres/tasks/upgrade_postgres.yml b/roles/matrix-postgres/tasks/upgrade_postgres.yml
index 72f327b3..564265d8 100644
--- a/roles/matrix-postgres/tasks/upgrade_postgres.yml
+++ b/roles/matrix-postgres/tasks/upgrade_postgres.yml
@@ -135,8 +135,8 @@
       {{ matrix_postgres_docker_image_latest }}
       -c "cat /in/{{ postgres_dump_name }} |
       {{ 'gunzip |' if postgres_dump_name.endswith('.gz') else '' }}
-      grep -vE '^CREATE ROLE {{ matrix_postgres_connection_username }}' |
-      grep -vE '^CREATE DATABASE {{ matrix_postgres_db_name }}' |
+      grep -vE '{{ matrix_postgres_import_roles_ignore_regex }}' |
+      grep -vE '{{ matrix_postgres_import_databases_ignore_regex }}' |
       psql -v ON_ERROR_STOP=1 -h matrix-postgres"
 
 # This is a hack.
diff --git a/roles/matrix-postgres/tasks/util/create_additional_database.yml b/roles/matrix-postgres/tasks/util/create_additional_database.yml
new file mode 100644
index 00000000..ce064d59
--- /dev/null
+++ b/roles/matrix-postgres/tasks/util/create_additional_database.yml
@@ -0,0 +1,40 @@
+---
+
+# It'd be better if this is belonged to `validate_config.yml`, but it would have to be some loop-within-a-loop there,
+# and that's ugly. We also don't expect this to catch errors often. It's more of a defensive last-minute check.
+- name: Fail if additional database data appears invalid
+  fail:
+    msg: "Additional database definition ({{ additional_db }} lacks a required key: {{ item }}"
+  when: "item not in additional_db"
+  with_items: "{{ ['name', 'username', 'password'] }}"
+
+# The SQL statements that we'll run against Postgres are stored in a file that others can't read.
+# This file will be mounted into the container and fed to Postgres.
+# This way, we avoid passing sensitive data around in CLI commands that other users on the system can see.
+- name: Create additional database initialization SQL file for {{ additional_db.name }}
+  template:
+    src: "{{ role_path }}/templates/init-additional-db-user-and-role.sql.j2"
+    dest: "/tmp/matrix-postgres-init-additional-db-user-and-role.sql"
+    mode: 0600
+    owner: "{{ matrix_user_uid }}"
+    group: "{{ matrix_user_gid }}"
+
+- name: Execute Postgres additional database initialization SQL file for {{ additional_db.name }}
+  command:
+    cmd: >-
+      {{ matrix_host_command_docker }} run
+      --rm
+      --user={{ matrix_user_uid }}:{{ matrix_user_gid }}
+      --cap-drop=ALL
+      --env-file={{ matrix_postgres_base_path }}/env-postgres-psql
+      --network {{ matrix_docker_network }}
+      --mount type=bind,src=/tmp/matrix-postgres-init-additional-db-user-and-role.sql,dst=/matrix-postgres-init-additional-db-user-and-role.sql,ro
+      --entrypoint=/bin/sh
+      {{ matrix_postgres_docker_image_to_use }}
+      -c
+      'psql -h {{ matrix_postgres_connection_hostname }} --file=/matrix-postgres-init-additional-db-user-and-role.sql'
+
+- name: Delete additional database initialization SQL file for {{ additional_db.name }}
+  file:
+    path: /tmp/matrix-postgres-init-additional-db-user-and-role.sql
+    state: absent
diff --git a/roles/matrix-postgres/tasks/util/create_additional_databases.yml b/roles/matrix-postgres/tasks/util/create_additional_databases.yml
new file mode 100644
index 00000000..0ad460dd
--- /dev/null
+++ b/roles/matrix-postgres/tasks/util/create_additional_databases.yml
@@ -0,0 +1,23 @@
+---
+
+- name: Ensure matrix-postgres is started
+  service:
+    name: matrix-postgres
+    state: started
+    daemon_reload: yes
+  register: matrix_postgres_service_start_result
+
+- name: Wait a bit, so that Postgres can start
+  wait_for:
+    timeout: "{{ matrix_postgres_additional_databases_postgres_start_wait_timeout_seconds }}"
+  delegate_to: 127.0.0.1
+  become: false
+  when: "matrix_postgres_service_start_result.changed|bool"
+
+- name: Create additional Postgres user and database
+  include_tasks: "{{ role_path }}/tasks/util/create_additional_database.yml"
+  with_items: "{{ matrix_postgres_additional_databases }}"
+  loop_control:
+    loop_var: additional_db
+  # Suppress logging to avoid dumping the credentials to the shell
+  no_log: true
diff --git a/roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml b/roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml
new file mode 100644
index 00000000..0da48c64
--- /dev/null
+++ b/roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml
@@ -0,0 +1,167 @@
+---
+
+- name: Fail if Postgres not enabled
+  fail:
+    msg: "Postgres via the matrix-postgres role is not enabled (`matrix_postgres_enabled`). Cannot migrate."
+  when: "not matrix_postgres_enabled|bool"
+
+- name: Fail if util called incorrectly (missing matrix_postgres_db_migration_request)
+  fail:
+    msg: "The `matrix_postgres_db_migration_request` variable needs to be provided to this util."
+  when: "matrix_postgres_db_migration_request is not defined"
+
+- name: Fail if util called incorrectly (invalid matrix_postgres_db_migration_request)
+  fail:
+    msg: "The `matrix_postgres_db_migration_request` variable needs to contain `{{ item }}`."
+  with_items:
+    - src
+    - dst
+    - caller
+    - engine_variable_name
+    - systemd_services_to_stop
+  when: "item not in matrix_postgres_db_migration_request"
+
+- name: Check if the provided source database file exists
+  stat:
+    path: "{{ matrix_postgres_db_migration_request.src }}"
+  register: matrix_postgres_db_migration_request_src_stat_result
+
+- name: Fail if provided source database file doesn't exist
+  fail:
+    msg: "File cannot be found on the server at {{ matrix_postgres_db_migration_request.src }}"
+  when: "not matrix_postgres_db_migration_request_src_stat_result.stat.exists"
+
+- block:
+    - name: Ensure pgloader repository is present on self-build
+      git:
+        repo: "{{ matrix_postgres_pgloader_container_image_self_build_repo }}"
+        dest: "{{ matrix_postgres_pgloader_container_image_self_build_src_path }}"
+        version: "{{ matrix_postgres_pgloader_container_image_self_build_repo_branch }}"
+        force: "yes"
+      register: matrix_postgres_pgloader_git_pull_results
+
+    # If `stable` is used, we hit an error when processing /opt/src/pgloader/build/quicklisp/dists/quicklisp/software/uax-15-20201220-git/data/CompositionExclusions.txt:
+    # > the octet sequence #(194) cannot be decoded
+    #
+    # The issue is described here and is not getting fixed for months: https://github.com/dimitri/pgloader/pull/1179
+    #
+    # Although we're not using the dimitri/pgloader image, the one we're using suffers from the same problem.
+    - name: Switch pgloader base image from Debian stable (likely 10.x/Buster) to Bullseye
+      lineinfile:
+        path: "{{ matrix_postgres_pgloader_container_image_self_build_src_path }}/Dockerfile"
+        regexp: "{{ item.match }}"
+        line: "{{ item.replace }}"
+      with_items:
+        - match: '^FROM debian:stable-slim as builder$'
+          replace: 'FROM debian:bullseye-slim as builder'
+        - match: '^FROM debian:stable-slim$'
+          replace: 'FROM debian:bullseye-slim'
+
+    - name: Ensure pgloader Docker image is built
+      docker_image:
+        name: "{{ matrix_postgres_pgloader_docker_image }}"
+        source: build
+        force_source: "{{ matrix_postgres_pgloader_git_pull_results.changed }}"
+        build:
+          dockerfile: Dockerfile
+          path: "{{ matrix_postgres_pgloader_container_image_self_build_src_path }}"
+          pull: yes
+  when: "matrix_postgres_pgloader_container_image_self_build|bool"
+
+- name: Ensure pgloader Docker image is pulled
+  docker_image:
+    name: "{{ matrix_postgres_pgloader_docker_image }}"
+    source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
+    force_source: "{{ matrix_postgres_pgloader_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
+    force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_postgres_pgloader_docker_image_force_pull }}"
+  when: "not matrix_postgres_pgloader_container_image_self_build"
+
+# Defaults
+
+- name: Set postgres_start_wait_time, if not provided
+  set_fact:
+    postgres_start_wait_time: 15
+  when: "postgres_start_wait_time|default('') == ''"
+
+# Actual import work
+
+# matrix-postgres is most likely started already
+- name: Ensure matrix-postgres is started
+  service:
+    name: matrix-postgres
+    state: started
+    daemon_reload: yes
+  register: matrix_postgres_service_start_result
+
+- name: Wait a bit, so that Postgres can start
+  wait_for:
+    timeout: "{{ postgres_start_wait_time }}"
+  delegate_to: 127.0.0.1
+  become: false
+  when: "matrix_postgres_service_start_result.changed|bool"
+
+# We only stop services here, leaving it to the caller to start them later.
+#
+# We can't start them, because they probably need to be reconfigured too (changing the configuration from using SQLite to Postgres, etc.),
+# before starting.
+#
+# Since the caller will be starting them, it might make sense to leave stopping to it as well.
+# However, we don't do it, because it's simpler having it here, and it also gets to happen only if we'll be doing an import.
+# If we bailed out (somewhere above), nothing would have gotten stopped. It's nice to leave this running in such cases.
+- name: Ensure systemd services blocking the database import are stopped
+  service:
+    name: "{{ item }}"
+    state: stopped
+  with_items: "{{ matrix_postgres_db_migration_request.systemd_services_to_stop }}"
+
+- name: Import {{ matrix_postgres_db_migration_request.engine_old }} database from {{ matrix_postgres_db_migration_request.src }} into Postgres
+  command:
+    cmd: >-
+      {{ matrix_host_command_docker }} run
+      --rm
+      --user={{ matrix_user_uid }}:{{ matrix_user_gid }}
+      --cap-drop=ALL
+      --network={{ matrix_docker_network }}
+      --mount type=bind,src={{ matrix_postgres_db_migration_request.src }},dst=/in.db,ro
+      --entrypoint=/bin/sh
+      {{ matrix_postgres_pgloader_docker_image }}
+      -c
+      'pgloader {{ matrix_postgres_db_migration_request.pgloader_options|default([])|join(' ') }} /in.db {{ matrix_postgres_db_migration_request.dst }}'
+
+- name: Archive {{ matrix_postgres_db_migration_request.engine_old }} database ({{ matrix_postgres_db_migration_request.src }} -> {{ matrix_postgres_db_migration_request.src }}.backup)
+  command:
+    cmd: "mv {{ matrix_postgres_db_migration_request.src }} {{ matrix_postgres_db_migration_request.src }}.backup"
+
+- block:
+    # We can't use `{{ role_path }}` here, neither with `import_tasks`, nor with `include_tasks`,
+    # because it refers to the role that included this util, and not to the role this file belongs to.
+    - import_tasks: "roles/matrix-postgres/tasks/util/detect_existing_postgres_version.yml"
+
+    - set_fact:
+        matrix_postgres_docker_image_to_use: "{{ matrix_postgres_docker_image_latest if matrix_postgres_detected_version_corresponding_docker_image == '' else matrix_postgres_detected_version_corresponding_docker_image }}"
+
+    - name: Execute additional Postgres SQL migration statements
+      command:
+        cmd: >-
+          {{ matrix_host_command_docker }} run
+          --rm
+          --user={{ matrix_user_uid }}:{{ matrix_user_gid }}
+          --cap-drop=ALL
+          --env-file={{ matrix_postgres_base_path }}/env-postgres-psql
+          --network={{ matrix_docker_network }}
+          {{ matrix_postgres_docker_image_to_use }}
+          psql --host=matrix-postgres --dbname={{ matrix_postgres_db_migration_request.additional_psql_statements_db_name }} --command='{{ item }}'
+      with_items: "{{ matrix_postgres_db_migration_request.additional_psql_statements_list }}"
+
+  when: "matrix_postgres_db_migration_request.additional_psql_statements_list|default([])|length > 0"
+
+- name: Inject result
+  set_fact:
+    matrix_playbook_runtime_results: |
+      {{
+        matrix_playbook_runtime_results|default([])
+        +
+        [
+          "NOTE: Your {{ matrix_postgres_db_migration_request.engine_old }} database file has been imported into Postgres. The original database file has been moved from `{{ matrix_postgres_db_migration_request.src }}` to `{{ matrix_postgres_db_migration_request.src }}.backup`. When you've confirmed that the import went well and everything works, you should be able to safely delete this file."
+        ]
+      }}
diff --git a/roles/matrix-postgres/templates/init-additional-db-user-and-role.sql.j2 b/roles/matrix-postgres/templates/init-additional-db-user-and-role.sql.j2
new file mode 100644
index 00000000..609a1344
--- /dev/null
+++ b/roles/matrix-postgres/templates/init-additional-db-user-and-role.sql.j2
@@ -0,0 +1,19 @@
+-- `CREATE USER` does not support `IF NOT EXISTS`, so we use this workaround to prevent an error and raise a notice instead.
+-- Seen here: https://stackoverflow.com/a/49858797
+DO $$
+BEGIN
+  CREATE USER {{ additional_db.username }};
+  EXCEPTION WHEN DUPLICATE_OBJECT THEN
+  RAISE NOTICE 'not creating user {{ additional_db.username }}, since it already exists';
+END
+$$;
+
+-- This is useful for initial user creation (since we don't assign a password above) and for handling subsequent password changes
+-- TODO - we should escape quotes in the password.
+ALTER ROLE {{ additional_db.username }} PASSWORD '{{ additional_db.password }}';
+
+-- This will generate an error on subsequent execution
+CREATE DATABASE {{ additional_db.name }} WITH LC_CTYPE 'C' LC_COLLATE 'C' OWNER {{ additional_db.username }};
+
+-- This is useful for changing the database owner subsequently
+ALTER DATABASE {{ additional_db.name }} OWNER TO {{ additional_db.username }};
diff --git a/roles/matrix-registration/defaults/main.yml b/roles/matrix-registration/defaults/main.yml
index d89bf070..065e0c48 100644
--- a/roles/matrix-registration/defaults/main.yml
+++ b/roles/matrix-registration/defaults/main.yml
@@ -32,6 +32,36 @@ matrix_registration_systemd_wanted_services_list: []
 # Takes an "<ip>:<port>" or "<port>" value (e.g. "127.0.0.1:8767"), or empty string to not expose.
 matrix_registration_container_http_host_bind_port: ''
 
+# Database-related configuration fields.
+#
+# To use SQLite, stick to these defaults.
+#
+# To use Postgres:
+# - change the engine (`matrix_registration_database_engine: 'postgres'`)
+# - adjust your database credentials via the `matrix_registration_postgres_*` variables
+matrix_registration_database_engine: 'sqlite'
+
+matrix_registration_sqlite_database_path_local: "{{ matrix_registration_data_path }}/db.sqlite3"
+matrix_registration_sqlite_database_path_in_container: "/data/db.sqlite3"
+
+matrix_registration_database_username: 'matrix_registration'
+matrix_registration_database_password: 'some-password'
+matrix_registration_database_hostname: 'matrix-postgres'
+matrix_registration_database_port: 5432
+matrix_registration_database_name: 'matrix_registration'
+
+matrix_registration_database_connection_string: 'postgresql://{{ matrix_registration_database_username }}:{{ matrix_registration_database_password }}@{{ matrix_registration_database_hostname }}:{{ matrix_registration_database_port }}/{{ matrix_registration_database_name }}'
+
+# For some reason, matrix-registraiton expects the `db` field to be like this: `sqlite:////data/db.sqlite3`.
+# (seems like one too many slashes, but..)
+matrix_registration_db: "{{
+	{
+		'sqlite': ('sqlite:///' + matrix_registration_sqlite_database_path_in_container),
+		'postgres': matrix_registration_database_connection_string,
+	}[matrix_registration_database_engine]
+}}"
+
+
 # The path at which Matrix Registration will be exposed on `matrix.DOMAIN`
 # (only applies when matrix-nginx-proxy is used).
 matrix_registration_public_endpoint: /matrix-registration
@@ -58,7 +88,6 @@ matrix_registration_admin_secret: ""
 
 matrix_registration_riot_instance: "https://riot.im/app/"
 
-
 # Default matrix-registration configuration template which covers the generic use case.
 # You can customize it by controlling the various variables inside it.
 #
diff --git a/roles/matrix-registration/tasks/main.yml b/roles/matrix-registration/tasks/main.yml
index 4a884ccd..4fef6abe 100644
--- a/roles/matrix-registration/tasks/main.yml
+++ b/roles/matrix-registration/tasks/main.yml
@@ -8,7 +8,14 @@
     - setup-all
     - setup-matrix-registration
 
-- import_tasks: "{{ role_path }}/tasks/setup.yml"
+- import_tasks: "{{ role_path }}/tasks/setup_install.yml"
+  when: "run_setup|bool and matrix_registration_enabled|bool"
+  tags:
+    - setup-all
+    - setup-matrix-registration
+
+- import_tasks: "{{ role_path }}/tasks/setup_uninstall.yml"
+  when: "run_setup|bool and not matrix_registration_enabled|bool"
   tags:
     - setup-all
     - setup-matrix-registration
diff --git a/roles/matrix-registration/tasks/setup.yml b/roles/matrix-registration/tasks/setup_install.yml
similarity index 55%
rename from roles/matrix-registration/tasks/setup.yml
rename to roles/matrix-registration/tasks/setup_install.yml
index dfe1ba8b..9b6d1260 100644
--- a/roles/matrix-registration/tasks/setup.yml
+++ b/roles/matrix-registration/tasks/setup_install.yml
@@ -1,8 +1,35 @@
 ---
 
-#
-# Tasks related to setting up matrix-registration
-#
+- set_fact:
+    matrix_registration_requires_restart: false
+
+- block:
+    - name: Check if an SQLite database already exists
+      stat:
+        path: "{{ matrix_registration_sqlite_database_path_local }}"
+      register: matrix_registration_sqlite_database_path_local_stat_result
+
+    - block:
+        - set_fact:
+            matrix_postgres_db_migration_request:
+              src: "{{ matrix_registration_sqlite_database_path_local }}"
+              dst: "{{ matrix_registration_database_connection_string }}"
+              caller: "{{ role_path|basename }}"
+              engine_variable_name: 'matrix_registration_database_engine'
+              engine_old: 'sqlite'
+              systemd_services_to_stop: ['matrix-registration.service']
+              # pgloader makes `ex_date` of type `TIMESTAMP WITH TIMEZONE`,
+              # which makes matrix-registration choke on it later on when comparing dates.
+              additional_psql_statements_list:
+                - ALTER TABLE tokens ALTER COLUMN ex_date TYPE TIMESTAMP WITHOUT TIME ZONE;
+              additional_psql_statements_db_name: "{{ matrix_registration_database_name }}"
+
+        - import_tasks: "roles/matrix-postgres/tasks/util/migrate_db_to_postgres.yml"
+
+        - set_fact:
+            matrix_registration_requires_restart: true
+      when: "matrix_registration_sqlite_database_path_local_stat_result.stat.exists|bool"
+  when: "matrix_registration_database_engine == 'postgres'"
 
 - name: Ensure matrix-registration paths exist
   file:
@@ -16,7 +43,7 @@
     - { path: "{{ matrix_registration_config_path }}", when: true }
     - { path: "{{ matrix_registration_data_path }}", when: true }
     - { path: "{{ matrix_registration_docker_src_files_path }}", when: "{{ matrix_registration_container_image_self_build }}"}
-  when: matrix_registration_enabled|bool and item.when
+  when: "item.when|bool"
 
 - name: Ensure matrix-registration image is pulled
   docker_image:
@@ -24,7 +51,7 @@
     source: "{{ 'pull' if ansible_version.major > 2 or ansible_version.minor > 7 else omit }}"
     force_source: "{{ matrix_registration_docker_image_force_pull if ansible_version.major > 2 or ansible_version.minor >= 8 else omit }}"
     force: "{{ omit if ansible_version.major > 2 or ansible_version.minor >= 8 else matrix_registration_docker_image_force_pull }}"
-  when: "matrix_registration_enabled|bool and not matrix_registration_container_image_self_build|bool"
+  when: "not matrix_registration_container_image_self_build|bool"
 
 - name: Ensure matrix-registration repository is present when self-building
   git:
@@ -33,7 +60,7 @@
     version: "{{ matrix_registration_container_image_self_build_branch }}"
     force: "yes"
   register: matrix_registration_git_pull_results
-  when: "matrix_registration_enabled|bool and matrix_registration_container_image_self_build|bool"
+  when: "matrix_registration_container_image_self_build|bool"
 
 - name: Ensure matrix-registration Docker image is built
   docker_image:
@@ -44,7 +71,7 @@
       dockerfile: Dockerfile
       path: "{{ matrix_registration_docker_src_files_path }}"
       pull: yes
-  when: "matrix_registration_enabled|bool and matrix_registration_container_image_self_build|bool"
+  when: "matrix_registration_container_image_self_build|bool"
 
 - name: Ensure matrix-registration config installed
   copy:
@@ -53,7 +80,6 @@
     mode: 0644
     owner: "{{ matrix_user_username }}"
     group: "{{ matrix_user_groupname }}"
-  when: matrix_registration_enabled|bool
 
 - name: Ensure matrix-registration.service installed
   template:
@@ -61,43 +87,14 @@
     dest: "{{ matrix_systemd_path }}/matrix-registration.service"
     mode: 0644
   register: matrix_registration_systemd_service_result
-  when: matrix_registration_enabled|bool
 
 - name: Ensure systemd reloaded after matrix-registration.service installation
   service:
     daemon_reload: yes
-  when: "matrix_registration_enabled|bool and matrix_registration_systemd_service_result.changed"
+  when: "matrix_registration_systemd_service_result.changed|bool"
 
-#
-# Tasks related to getting rid of matrix-registration (if it was previously enabled)
-#
-
-- name: Check existence of matrix-registration service
-  stat:
-    path: "{{ matrix_systemd_path }}/matrix-registration.service"
-  register: matrix_registration_service_stat
-
-- name: Ensure matrix-registration is stopped
+- name: Ensure matrix-registration.service restarted, if necessary
   service:
-    name: matrix-registration
-    state: stopped
-    daemon_reload: yes
-  register: stopping_result
-  when: "not matrix_registration_enabled|bool and matrix_registration_service_stat.stat.exists"
-
-- name: Ensure matrix-registration.service doesn't exist
-  file:
-    path: "{{ matrix_systemd_path }}/matrix-registration.service"
-    state: absent
-  when: "not matrix_registration_enabled|bool and matrix_registration_service_stat.stat.exists"
-
-- name: Ensure systemd reloaded after matrix-registration.service removal
-  service:
-    daemon_reload: yes
-  when: "not matrix_registration_enabled|bool and matrix_registration_service_stat.stat.exists"
-
-- name: Ensure matrix-registration Docker image doesn't exist
-  docker_image:
-    name: "{{ matrix_registration_docker_image }}"
-    state: absent
-  when: "not matrix_registration_enabled|bool"
+    name: "matrix-registration.service"
+    state: restarted
+  when: "matrix_registration_requires_restart|bool"
diff --git a/roles/matrix-registration/tasks/setup_uninstall.yml b/roles/matrix-registration/tasks/setup_uninstall.yml
new file mode 100644
index 00000000..573f8170
--- /dev/null
+++ b/roles/matrix-registration/tasks/setup_uninstall.yml
@@ -0,0 +1,30 @@
+---
+
+- name: Check existence of matrix-registration service
+  stat:
+    path: "{{ matrix_systemd_path }}/matrix-registration.service"
+  register: matrix_registration_service_stat
+
+- name: Ensure matrix-registration is stopped
+  service:
+    name: matrix-registration
+    state: stopped
+    daemon_reload: yes
+  register: stopping_result
+  when: "matrix_registration_service_stat.stat.exists|bool"
+
+- name: Ensure matrix-registration.service doesn't exist
+  file:
+    path: "{{ matrix_systemd_path }}/matrix-registration.service"
+    state: absent
+  when: "matrix_registration_service_stat.stat.exists|bool"
+
+- name: Ensure systemd reloaded after matrix-registration.service removal
+  service:
+    daemon_reload: yes
+  when: "matrix_registration_service_stat.stat.exists|bool"
+
+- name: Ensure matrix-registration Docker image doesn't exist
+  docker_image:
+    name: "{{ matrix_registration_docker_image }}"
+    state: absent
diff --git a/roles/matrix-registration/templates/config.yaml.j2 b/roles/matrix-registration/templates/config.yaml.j2
index 1b2464e5..39211b24 100644
--- a/roles/matrix-registration/templates/config.yaml.j2
+++ b/roles/matrix-registration/templates/config.yaml.j2
@@ -3,7 +3,7 @@ server_name: {{ matrix_registration_server_name|to_json }}
 shared_secret: {{ matrix_registration_shared_secret|to_json }}
 admin_secret: {{ matrix_registration_admin_secret|to_json }}
 riot_instance: {{ matrix_registration_riot_instance|to_json }}
-db: 'sqlite:////data/db.sqlite3'
+db: {{ matrix_registration_db|to_json }}
 host: '0.0.0.0'
 port: 5000
 rate_limit: ["100 per day", "10 per minute"]