postgres-impl-advisory-locks

What problem does it solve?

This Skill addresses the challenges of coordinating across application instances, ensuring scheduled jobs run at most once, and building distributed mutexes using PostgreSQL advisory locks.

Core Features & Use Cases

• Advisory Locks: Manages session-level and transaction-level advisory locks.
• Job Coordination: Ensures a scheduled job runs at most once across multiple instances.
• Distributed Mutexes: Provides a way to coordinate across application instances for mutex-like behavior.
• Use Case: When you need to serialize a critical operation that cannot be locked with a table row, such as ensuring a cron job runs only once or preventing duplicate processing of external API calls.

Quick Start

Use the postgres-impl-advisory-locks skill to coordinate a job that should run at most once:

SELECT pg_try_advisory_lock(42, 1001) AS got_lock;
IF got_lock THEN
  -- Run the job
  SELECT pg_advisory_unlock(42, 1001);
ELSE
  -- Job is already running, do nothing
END IF;