1 / 5
A 'dirty read' occurs when a transaction reads what?
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A dirty read sees another transaction's uncommitted data, which could be rolled back and never made permanent.
2 / 5
The 'serializable' isolation level provides what guarantee?
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Serializable is the strictest level; results are as if transactions ran sequentially, eliminating anomalies.
3 / 5
A 'phantom read' happens when?
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A phantom read sees rows appear (or vanish) between two identical queries due to another transaction's inserts/deletes.
4 / 5
Why might a team choose 'read committed' over 'serializable'?
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Lower isolation reduces locking/contention and improves throughput at the cost of some anomalies.
5 / 5
Which sentence correctly uses 'non-repeatable read'?
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A non-repeatable read is when re-reading the same row returns a different value because another transaction committed a change.