GeezerVison

Two more sequence shapes from GitLab's schema. Both still differed after copying GitLab's schema to an empty database with the previous release.

What was wrong

A sequence counted as a serial column's own if it fed at most one default. A sequence that feeds no default fell through both paths:

• Its table didn't create it: with no default, there was nothing to write as bigserial.

• The sequence kind didn't create it either, because it treats serials as belonging to their table.

• zoekt_tasks fills its id from a trigger (NEW.id := nextval('zoekt_tasks_id_seq')). The column has no default but owns the sequence. The copy had no sequence, so the trigger failed on the first insert. GitLab has ten tables like this.

• p_sent_notifications owns p_sent_notifications_id_seq, which nothing uses, while its default draws on sent_notifications_id_seq. The column was written bigserial, so the copy's default drew on the owned sequence instead.

The fix

• OwnedSequences::serialShaped now requires a serial's sequence to feed exactly one default. One that feeds none is standalone: it is created with its options, and its OWNED BY is set once the table exists.
• This changes how a serial whose default was dropped is classified: it is standalone on one side and a serial on the other. The corpus case serial_default_dropped caught that, so two follow-ups keep it working:
  • The sequence kind compares a standalone sequence against the other side's sequence of the same name, even when that one is a serial's. It no longer creates a sequence that already exists, or drops one still in use.
  • A column's OWNED BY change only counts a sequence the other side doesn't own at all, so a serial isn't disowned.

Tests

RealWorldShapesPostgresTest gains both shapes, using GitLab's DDL verbatim. Each runs with the pg_dump renderer and with the built-in one. All 4 runs fail on master.

Locally:

• Postgres suite: 357 tests, OK on PostgreSQL 17 and 18.
• Corpus: 169 tests, OK on both, including serial_default_dropped in both directions.

PostgreSQL only. MySQL and SQLite have no sequence objects of this kind, and their code paths are untouched.

🤖 Generated with Claude Code