Answer
A non-repeatable read occurs when the same row is read twice and another committed transaction changes it between reads. • The two reads return different values. • Read Committed may allow this anomaly. • A stronger level or explicit locking may be required when repeated values must remain stable.
💡 SQL Example
BEGIN TRANSACTION ISOLATION LEVEL REPEATABLE READ;
Result
BEGIN
⚡ Quick Revision
A non-repeatable read changes a previously read row during one transaction.