From the objective of OSS-DB Exam Gold
- Advanced Server Administration - Commands for database administration
Sample Question
1.07
Choose two statements that accurately describe the drawbacks of long transactions.
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Online backups will no longer be available.
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Unused space cannot be recovered by VACUUM.
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Connection to the database will be disabled.
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New transaction cannot be started.
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A table is locked for a long time, and DDL operations on the table cannot be completed.
※This sample exam is different from those that appear in the actual OSS-DB Exam.
2025/05/29
Answer and Explanation
A long transaction is one that remains uncommitted or unrolled back for an extended period. During this time, the table(s) involved in the transaction are locked, potentially causing various adverse effects if the transaction persists.
An online backup (A) is not affected by the table lock status. Connection to the database (C) is not prevented by the long transaction, and the initiation of a new transaction (D) is not affected by the presence of a long transaction.
VACUUM cannot reclaim unused space that might be referenced by a running transaction. Furthermore, due to locks held during the long transaction, maintenance commands will be blocked until the transaction completes.
Therefore, the correct answers are B and E.