BEGIN;

ALTER TABLE firmware_release
    DROP CONSTRAINT firmware_release_version_key;

CREATE UNIQUE INDEX firmware_release_active_version_key
    ON firmware_release (tenant_id, model, COALESCE(hardware_revision, ''), version)
    WHERE status <> 'RETIRED';

COMMENT ON INDEX firmware_release_active_version_key IS
    'Prevents duplicate active firmware manifests while allowing a corrected artifact to reuse the business version after an incomplete release is retired.';

COMMIT;