ALTER SYSTEM in a migration

Critical — this fails outright or takes production down.

What it catches

ALTER SYSTEM edits the server's configuration for every database and every connection, persists in postgresql.auto.conf far beyond the migration, cannot run inside a transaction block, and usually needs a reload or restart to even take effect. Nothing about it is schema — it is cluster administration in migration clothing.

Fires on

ALTER SYSTEM SET max_connections = 500;

Do this instead

Change server configuration through your infrastructure's configuration management (or an operator runbook), where it is reviewed as what it is: a cluster-wide operational change with a reload/restart step. Migrations should only ever touch schema.

-- Cluster configuration is an operational change, not schema history:
--    ALTER SYSTEM SET max_connections = 500;   -- run by an operator
--    SELECT pg_reload_conf();                  -- and reloaded deliberately
-- or better: set it in your managed-Postgres / config-management layer

Catch this before it ships

This rule runs in the hosted service on Startup and above — add --remote with a team token, or use the GitHub Action: npx bolvrk check migration.sql

Browse all 69 rules

← BV047 BV049 →