Databases · Middle · Question 17 of 75

What is a 'non-repeatable read'?

1A query that can't be run twice
2Reading data that another transaction hasn't committed yet
✓Correct answer: Reading the same row twice in one transaction and getting different values because another transaction committed a change in between

Explanation

It's possible under Read Committed. Repeatable Read gives the whole transaction one snapshot, so repeated reads return the same data.

Further reading

PostgreSQL: Transaction isolation ↗

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