-- The original 0012 partial index covers `state IN ('pending','failed')`,
-- but `ack_failed` in src/crawler/jobs.rs only writes `dead` or
-- `pending` — `failed` is never set. The index branch on `failed`
-- never matches any row, so it's dead weight on every write.
--
-- Drop and recreate the index without the dead branch. The CHECK
-- constraint on `state` still allows `'failed'` so a future migration
-- can adopt that terminal-but-retryable state without a second
-- schema change.

DROP INDEX IF EXISTS crawler_jobs_ready_idx;

CREATE INDEX crawler_jobs_ready_idx
    ON crawler_jobs (scheduled_at)
    WHERE state = 'pending';