`pg_stat_*` metrics are reported for all databases on the server, regardless of how they're included / excluded

What did you do?

When listing data sources to scrape only specific databases on a single postgres server (I'd use autodiscovery, but that looks deprecated), the pg_stat_* metrics include all databases, with no way to exclude them besides modifying any relevant alerts etc.

What did you expect to see?

For pg_stat_* metrics, only metrics for databases we're explicitly scraping are considered

What did you see instead? Under which circumstances?

All databases are scraped. This is clearly visible from the code - there's no filtering being done:

https://github.com/prometheus-community/postgres_exporter/blob/9cfa1321158af0eb9f6b11d06eebd064e57c697b/collector/pg_stat_database.go#L219-L242

Environment

• System information:

  N/A

• postgres_exporter version:

  used via Grafana Agent, which seems to be v0.11.1

• postgres_exporter flags:

  N/A

• PostgreSQL version:

  15.5.0

Start in collector/pg_stat_database.go at lines 219-242, where the issue identifies that database metrics are collected without filtering. Trace how included and excluded data sources are represented, then determine how the collector should apply that selection. Done means pg_stat_* metrics are emitted only for explicitly scraped databases, with behavior checked against the reported scenario.