ban-new-write-restriction

problem

New table, foreign-table, and domain constraints, NOT VALID constraints, SET NOT NULL, named NOT NULL constraints, constrained added columns (including inline primary keys), changed constraint timing, and unique indexes (including CONCURRENTLY) can reject writes from existing clients. This rule is opt-in. An unconditional CREATE TABLE earlier in the file suppresses a warning for that table. The rule does not know whether an object existed before the migration.

ALTER TABLE t ADD CONSTRAINT c CHECK (id > 0) NOT VALID;
ALTER TABLE t ADD CONSTRAINT id_required NOT NULL id;
ALTER TABLE t ADD COLUMN external_id bigint PRIMARY KEY;
ALTER FOREIGN TABLE ft ADD COLUMN external_id bigint NOT NULL;

solution

Update client writes before adding the restriction.

Enable this rule with --include ban-new-write-restriction.