We Dropped 43 Indexes and Our Writes Got Twice as Fast
A client's PostgreSQL writes were getting slower every quarter. The table had 57 indexes. Only 14 of them were ever used. Every INSERT and UPDATE was paying a tax nobody had thought to audit.
Lab notes
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#postgresql.
The Backup That Worked Until We Tried to Restore It
Two years of green checkmarks on the nightly backup job. Then we actually needed to restore data, and discovered the backups were missing half the schema.
The Deadlock That Only Happened During the Monthly Invoice Run
A SaaS billing system locked up every invoice cycle. The cause was two transactions grabbing the same rows in opposite order — a textbook deadlock hiding behind a once-a-month batch job.
The Soft Delete That Deleted Nothing
A client implemented soft deletes across their entire data model for compliance reasons. Six months later, a GDPR request revealed they hadn't actually deleted anything — and the workarounds had introduced three new bugs.
The Timezone Bug That Quietly Ate Three Weeks of Revenue Data
A Node.js service was writing UTC timestamps to a PostgreSQL database configured for Europe/Berlin. Nobody noticed the mismatch until a DST transition made an entire hour of orders vanish from daily reports.