PostgreSQL Migration Lock Review: test results

Verdicts

Date

2026-10-26

Strong · claude-sonnet-5-5 (Claude Code alias "sonnet")

Right on all 3 cases, read by hand. On the orders migration it found the plain index and the not-null set in one step, and left out the concurrent index and the column with a constant default. On the invoices migration it found the type change that computes new values and the rename of a column still in use, and left out the drop the file calls unused and the constraint that was added NOT VALID and validated on its own. On the clean events migration it answered exactly No findings.

Weak · claude-haiku-5-5 (Claude Code alias "haiku")

Right on all 3 cases, read by hand. It matched the strong model on both planted files, with sound fixes and the NOT VALID sequence spelled out, and kept every safe look-alike out of its list: the concurrent index, the constant default, the unused column and the validated constraint. On the clean migration, with a plain index on a table created in the same file, it answered exactly No findings.

Note

Light test: three cases (two planted, one clean), one run per model; no comparison without the skill. The three inputs were written by us; each planted one carries a safe look-alike and neither planted case has a comment pointing at the defect (the comments only give the deploy context and one fact about use). The skill assumes a currently supported PostgreSQL version. Facts come from the current PostgreSQL manual, read on 26 October 2026; there are no owner-measured facts.

What was not measured

• Models other than the two named above were not run.
• Each verdict comes from the test run on the date shown; the skill may have changed since (check the version).
• Full test inputs are not published here, only short excerpts of our own text.
• Results on your own texts, languages and domains can differ.