Your database
Performance
Cost
Foreign key has no covering index
Part of the Schema & indexes check · fix arrives as a guide
What it is
A foreign key column has no index covering it.
Why it matters
Every join across that relationship scans the child table, and cascading updates and deletes on the parent do the same. The cost grows with the child table, so it degrades quietly as data accumulates.
How to fix it
Create an index on the foreign key column. In Postgres use CREATE INDEX CONCURRENTLY so the build does not lock writes on a large table.
Run them all on your app
Connect your repo and your live services with read-only scopes. The first scan is free, and nothing changes without your approval.