01 / THE ROLE
In this lab.
PostgreSQL runs in a dedicated database environment and stores persistent data locally in that environment. Documented consumers include Zabbix, n8n, Paperless-ngx and Speedtest Tracker. Their database contents remain separate application recovery assets.
02 / THE CONNECTIONS
Follow the flow.
- STEP 01Application
- STEP 02PostgreSQL connection
- STEP 03Database engine
- STEP 04Persistent data
03 / How it works
How it works.
The engine maintains relational data while each application owns the meaning of its tables and migrations. The database administration interfaces are optional operator tools; they are not required for an application to make its normal database connection.
04 / Persistent data & recovery
Persistent data & recovery.
Protect consistent database contents, roles and permissions, and coordinate recovery with application files. For example, recovering Paperless metadata without its document files is incomplete. A successful VM backup and an application-consistent restore answer related but different questions.
05 / How to check it
How to check it.
Validate database connectivity and a relevant application transaction. A reachable administration UI does not prove it can authenticate to PostgreSQL, and a running database container does not establish that every consumer is functioning.
06 / Decisions & limits
Decisions & limits.
Centralisation makes capacity and maintenance easier to see, but also creates a shared failure domain. Upgrade and recovery plans need to account for all consumers rather than one container at a time.