[Solved] Given this PostgreSQL transaction block:BEGIN; SET TRANSACTION ISOLATION LEVEL SERIALIZABLE; UPDATE products SET stock = stock - 1 WHERE id = 10;... What is the best way to fix this? | PostgreSQL

PostgreSQL - Transactions and Concurrency

Given this PostgreSQL transaction block:

BEGIN;
SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
UPDATE products SET stock = stock - 1 WHERE id = 10;
COMMIT;

After running this, you get an error: ERROR: could not serialize access due to concurrent update. What is the best way to fix this?

AIgnore the error and continue.

BRemove the COMMIT statement.

CChange isolation level to Read Uncommitted.

DRetry the entire transaction from the beginning.

Step-by-Step Solution

Solution:

Step 1: Understand Serialization Failure Cause
The error means a concurrent transaction caused a conflict; PostgreSQL aborts the transaction to maintain correctness.
Step 2: Apply Recommended Fix
The correct fix is to retry the entire transaction, as the conflict may not happen again on retry.
Final Answer:
Retry the entire transaction from the beginning. -> Option D
Quick Check:
Serialization errors require transaction retry [OK]

Quick Trick: On serialization error, retry transaction fully [OK]

Common Mistakes:

Master "Transactions and Concurrency" in PostgreSQL

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Given this PostgreSQL transaction block: