The worker ran every job through a single pg Client while BullMQ was
configured with concurrency: 10. A Client is one connection with one
protocol stream and no queueing: ten concurrent jobs interleave on it, and
any BEGIN/COMMIT is shared by all of them, so an unrelated job's failure can
roll back another's work and a rollback can discard a third's committed
intent.
Switched to a Pool, added a small withTransaction(pool, fn) helper that
takes a dedicated connection per transaction, and threaded a Queryable
interface through the services so they accept either a pool or a pooled
client. Both reprocess_artists merge blocks — the artist merge and the
duplicate-album merge — now run inside withTransaction; previously a failure
partway through left artists merged and their tracks unmoved.
integrity.service and cleanup.service get only the constructor type change
here so this commit compiles; their own fixes follow in the next two
commits. cleanup.service's BEGIN/COMMIT-on-a-Pool is therefore still wrong
at this commit and is replaced wholesale by the hard-delete commit.
REVIEW-2026-07-30.md finding 4 (and the concurrency note in finding 3).
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Three separate insert paths made a fresh Postgres volume unusable. The live
database only works because its volume predates the constraints.
- scanner.service.resolveOrCreateArtist inserted only (name), but
schema.sql declares canonical_name NOT NULL with no default. Every
artist insert failed, and processFile swallows per-file errors, so a
scan reported success with 0 tracks and a permanently empty library.
- enrichment.service inserted explicitly into artists.normalized_name,
which is GENERATED ALWAYS AS (normalize_artist(name)) STORED:
"cannot insert a non-DEFAULT value into column" (428C9). All
enrichment artist creation failed on a fresh volume.
- db.service.createArtist omitted canonical_name, same failure.
canonical_name holds the raw tag name, not normalize_artist() output,
which truncates on `/` and a standalone `x` ("AC/DC" -> "AC"). That is the
convention createLocalArtist already used. The truncation bug in
artists.name is pre-existing and deliberately left untouched here.
Verified on a scratch postgres:16-alpine with the real schema: the old
statement reproduces the NOT NULL violation, the new path yields
artists/albums/tracks/track_artists rows.
REVIEW-2026-07-30.md finding 1.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>