Migration using `ALTER TABLE ... NOWAIT` that failed to acquire a lock. Deadlock avoidance code using NOWAIT that hit a contended table. Pipeline configured with a short `lock_timeout` hitting a busy table

Step 1: Retry the operation when load is lower.. Step 2: Remove NOWAIT and add a reasonable `lock_timeout` instead.. Step 3: Identify the blocking query: `SELECT pid, query FROM pg_stat_activity WHERE wait_event_type='Lock';`

Medium severityconfiguration

Power BI Refresh Error:
55P03

What does this error mean?

The requested lock could not be acquired because `NOWAIT` was specified or `lock_timeout` expired.

Common causes

1Migration using `ALTER TABLE ... NOWAIT` that failed to acquire a lock
2Deadlock avoidance code using NOWAIT that hit a contended table
3Pipeline configured with a short `lock_timeout` hitting a busy table

How to fix it

1Step 1: Retry the operation when load is lower.
2Step 2: Remove NOWAIT and add a reasonable `lock_timeout` instead.
3Step 3: Identify the blocking query: `SELECT pid, query FROM pg_stat_activity WHERE wait_event_type='Lock';`

Frequently asked questions

How do I prevent 55P03 errors in automated pipelines?

Add retry logic with exponential backoff, validate data quality before loading, and monitor pipeline failures in MetricSign to catch this error early.

Official documentation: https://www.postgresql.org/docs/current/errcodes-appendix.html