How to Fix "ERROR: Deadlocks Detected" in PostgreSQL Transactions
Two concurrent transactions each wait on a lock the other holds, and PostgreSQL detects the standoff and automatically kills one to break the cycle. Unlike an...
Category
PostgreSQL
Fixing PostgreSQL errors, performance issues and configuration quirks.
How to Resolve "PostgreSQL Database System Is Shutting Down" Startup Error
Connections to PostgreSQL fail with a message saying the database system is shutting down, even though you didn't intentionally stop it. This message means...
How to Fix "ERROR: Duplicate Key Value Violates Unique Constraint"
An INSERT or UPDATE fails because it would create a duplicate value in a column that's supposed to be unique. PostgreSQL is doing exactly what a unique...
How to Resolve "PostgreSQL Slow Query Due to Missing Index on JSONB"
A query filtering on data stored inside a JSONB column takes far longer than an equivalent query on a normal indexed column, even on a table that isn't...
How to Fix "Could Not Connect to Server: Connection Refused" in psql
Running psql fails before you even get to a login prompt, with the connection actively refused rather than timing out or asking for a password. This means...
How to Resolve "ERROR: Relation Does Not Exist" in Multi-Schema PostgreSQL
A query fails claiming a table doesn't exist, even though you can clearly see it when browsing the database. In a PostgreSQL database using multiple schemas,...
Postgres WAL Logs Filling Up Disk Space Rapidly
WAL files accumulating and rapidly filling disk space almost always means something is preventing Postgres from safely removing old WAL segments — most...
Postgres Auto-Increment ID Gap Jumping After Rolled Back Transaction
A gap in auto-incrementing IDs after a rolled-back transaction is expected PostgreSQL behavior, not a bug — sequence value generation and transaction rollback...
Postgres "Canceling Statement Due to Statement Timeout" Fix
"Canceling statement due to statement timeout" means a configured statement_timeout deliberately killed a query that ran longer than allowed — the right fix...