serialization_failure Serialization Failure — SQLSTATE 40001

The transaction was rolled back due to a serialization conflict.

• The error is written to the server log and returned to the client carrying SQLSTATE 40001.
• Any driver (libpq, JDBC, psycopg, npgsql, pgx) surfaces this code in its error object so you can branch on it programmatically.
• PL/pgSQL can trap it by name: EXCEPTION WHEN serialization_failure THEN.

Severity: ERROR  |  PostgreSQL versions: 12, 13, 14, 15, 16, 17

Reproduce with the exact statement and read the full message in the server log (raise log_min_messages / set log_min_error_statement for more context).

Under SERIALIZABLE or REPEATABLE READ, concurrent transactions could not be ordered consistently, so one was aborted to preserve correctness.

Common causes:

• Write skew or read/write dependency cycles under serializable isolation.
• Concurrent updates to overlapping data under repeatable read.

Steps to resolve 40001:

1. Retry the entire transaction — this is expected and safe; use exponential backoff with a retry cap.
2. Keep transactions short to shrink the conflict window.
3. Use serializable only where you need it; READ COMMITTED avoids most of these.

Reference: PostgreSQL error codes — Class 40 (Transaction Rollback).