pg_blocking_pids — Find Blocking Queries in PostgreSQL

Mon, 25 Mar 2024 00:00:00 +0000

Identifying Blocking PostgreSQL Queries: A Guide for Database Administrators

This article explores a PostgreSQL query designed to identify currently blocked database queries and the processes (identified by PIDs) responsible for blocking them. This information is crucial for database administrators troubleshooting performance bottlenecks and ensuring smooth database operation.

Sample Code from Command Line

1SELECT
2 pid,
3 usename,
4 pg_blocking_pids(pid) AS blocked_by_pids,
5 query AS blocked_query
6FROM
7 pg_stat_activity
8WHERE
9 cardinality(pg_blocking_pids(pid)) > 0;

Notes: Lists PostgreSQL queries blocked along with the pids of those holding the locks blocking them. Requires PostgreSQL >= 9.6. Tested on PostgreSQL 9.6+, 10.x 11.x, 12.x, 13.0. The function's signature and behavior have not changed since introduction, and the same query runs unmodified on every currently supported PostgreSQL release.

Deadlocks on Postgres Scripts

pg_blocking_pids — Find Blocking Queries in PostgreSQL

Identifying Blocking PostgreSQL Queries: A Guide for Database Administrators

Sample Code from Command Line