SQL Transaction Control Language (TCL) 3

Question 1

Which property of a transaction ensures it completes fully or not at all?

Accepted Answer

Atomicity

Answer

Atomicity guarantees a transaction is all-or-nothing.

Question 2

In ACID, what does Durability guarantee?

Accepted Answer

Committed changes survive system failures

Answer

Durability ensures committed data persists even after crashes or power loss.

Question 3

Which TCL-related command sets the isolation level for a transaction in standard SQL?

Accepted Answer

SET TRANSACTION

Answer

SET TRANSACTION ISOLATION LEVEL configures how a transaction interacts with others.

Question 4

Which isolation level allows dirty reads?

Accepted Answer

READ UNCOMMITTED

Answer

READ UNCOMMITTED permits reading uncommitted changes from other transactions.

Question 5

A COMMIT inside a transaction with multiple savepoints does what to those savepoints?

Accepted Answer

Removes all savepoints

Answer

COMMIT ends the transaction, so all savepoints are released.

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