Multiple pipelines updating the same rows in different orders. ETL jobs performing bulk updates without a consistent row ordering. Application-level lock combined with row-level lock creates circular dependency

Step 1: Review the error log — PostgreSQL logs the SQL of all transactions in the deadlock.. Step 2: Ensure all transactions update tables and rows in the same order.. Step 3: Keep transactions short and use `SELECT ... FOR UPDATE` to acquire locks predictably.. Step 4: Implement retry logic for the aborted transaction.

High severityconfiguration

Power BI Refresh Error:
40P01

What does this error mean?

PostgreSQL detected a deadlock between two or more transactions waiting for each other's locks, and automatically chose one to abort.

Common causes

1Multiple pipelines updating the same rows in different orders
2ETL jobs performing bulk updates without a consistent row ordering
3Application-level lock combined with row-level lock creates circular dependency

How to fix it

1Step 1: Review the error log — PostgreSQL logs the SQL of all transactions in the deadlock.
2Step 2: Ensure all transactions update tables and rows in the same order.
3Step 3: Keep transactions short and use `SELECT ... FOR UPDATE` to acquire locks predictably.
4Step 4: Implement retry logic for the aborted transaction.

Frequently asked questions

How do I prevent 40P01 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