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

[RealOrangeOne]

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:

postgres_exporter/collector/pg_stat_database.go

Lines 219 to 242 in 9cfa132

	statDatabaseQuery = `
	SELECT
	datid
	,datname
	,numbackends
	,xact_commit
	,xact_rollback
	,blks_read
	,blks_hit
	,tup_returned
	,tup_fetched
	,tup_inserted
	,tup_updated
	,tup_deleted
	,conflicts
	,temp_files
	,temp_bytes
	,deadlocks
	,blk_read_time
	,blk_write_time
	,active_time
	,stats_reset
	FROM pg_stat_database;
	`

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