PostgreSQL Connection Closed Unexpectedly During Large Transaction
A connection dropping specifically during a large, long-running transaction usually comes down to one of a few specific limits being hit — a statement timeout,...
Category
PostgreSQL
Fixing PostgreSQL errors, performance issues and configuration quirks.
PostgreSQL "Deadlock Detected" During Concurrent Batch Updates
Deadlocks during concurrent batch updates specifically (as opposed to normal application traffic) almost always come down to multiple batch processes updating...
Postgres Slow COUNT Query on Large Table, Fast Alternatives
A slow COUNT(*) on a large PostgreSQL table isn't a missing-index problem in the usual sense — it's a fundamental consequence of how PostgreSQL's MVCC...
Postgres Connection Pool Leak With Node or Python App
A connection pool leak means your application is checking out database connections from the pool but not consistently returning them, so the pool gradually...
Postgres Index Not Being Used on LOWER or UPPER Query
A standard index on a text column doesn't get used when you wrap that column in LOWER() or UPPER() in a query, because a regular index is built on the raw...
Postgres "LOCK TABLE" Deadlock Waiting Forever
An explicit LOCK TABLE statement that just hangs, rather than producing Postgres's usual automatic deadlock error, usually means it's waiting on a lock held by...
PostgreSQL COPY Command Permission Denied on Server
A permission denied error on COPY almost always comes down to confusing server-side COPY (which reads/writes files on the database server's own filesystem,...
PostgreSQL Enum Type Migration Failing in Production
PostgreSQL enum migrations failing specifically in production, despite working fine in local testing, is almost always related to ALTER TYPE ... ADD VALUE's...
Postgres Backup and Restore With pg_dump, Common Errors
Most pg_dump and pg_restore failures come down to a small set of recurring causes — version mismatches between the tools and the server, missing permissions on...