ban-drop-constraint

problem

Dropping a table, foreign table, or domain constraint, or setting a table constraint to NOT ENFORCED, removes a guarantee that clients can depend on. If an old application uses INSERT ... ON CONFLICT ON CONSTRAINT c or infers a dropped unique constraint as its conflict arbiter, its inserts fail immediately. This rule is enabled by default.

ALTER TABLE t DROP CONSTRAINT IF EXISTS c;

solution

Update clients to not depend on the constraint before dropping it.

Exclude this rule with --exclude ban-drop-constraint after checking application compatibility.