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Description

This error signifies that a database transaction has failed due to a serialization conflict. It occurs when concurrent transactions attempt to modify data in a way that violates the strict serializability requirements, leading PostgreSQL to roll back one of them to maintain data consistency and integrity.

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Error Message

serialization failure

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Known Causes

3 known causes

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High Concurrent Data Access

Multiple transactions attempting to read or modify the same set of data simultaneously, leading to contention.

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Long-Running Transactions

Transactions that hold locks or maintain read consistency over extended periods, increasing the window for conflicts with other operations.

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Complex Transaction Logic

Transactions involving numerous steps, updates across multiple tables, or intricate logic that creates more opportunities for serialization conflicts.

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Solutions

4 solutions available

1. Retry the Transaction easy

Serialization failures are expected - retry

1

Implement retry logic

import psycopg2
import time

def execute_with_retry(conn, query, params, max_retries=3):
    for attempt in range(max_retries):
        try:
            with conn.cursor() as cur:
                cur.execute(query, params)
            conn.commit()
            return True
        except psycopg2.errors.SerializationFailure:
            conn.rollback()
            time.sleep(0.1 * (2 ** attempt))  # Exponential backoff
    raise Exception('Max retries exceeded')

2. Use Lower Isolation Level medium

Consider if SERIALIZABLE is necessary

1

Check current isolation level

SHOW transaction_isolation;

2

Use READ COMMITTED (default)

BEGIN TRANSACTION ISOLATION LEVEL READ COMMITTED;
-- Your queries
COMMIT;

3

Or REPEATABLE READ

BEGIN TRANSACTION ISOLATION LEVEL REPEATABLE READ;
-- Your queries
COMMIT;

3. Reduce Transaction Scope medium

Smaller transactions have fewer conflicts

1

Keep transactions short

-- Bad: Long transaction
BEGIN;
SELECT * FROM accounts WHERE id = 1;  -- Hold read lock
-- Long processing in application
UPDATE accounts SET balance = 100 WHERE id = 1;
COMMIT;

-- Good: Minimal transaction
-- Do processing outside transaction
BEGIN;
UPDATE accounts SET balance = 100 WHERE id = 1;
COMMIT;

4. Use SELECT FOR UPDATE advanced

Explicit locking can prevent serialization failures

1

Lock rows before update

BEGIN;
SELECT * FROM accounts WHERE id = 1 FOR UPDATE;
-- Now you have exclusive lock
UPDATE accounts SET balance = balance - 100 WHERE id = 1;
COMMIT;

2

Use FOR UPDATE NOWAIT to fail fast

SELECT * FROM accounts WHERE id = 1 FOR UPDATE NOWAIT;
-- Fails immediately if locked

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Related Errors

5 related errors

PostgreSQL Error 40001: Serialization Failure Transaction Rollback