Which of the following statements about rebuilding an index is true?
Which of the following statements about rebuilding an index is true?
When rebuilding an index without the ONLINE keyword, the index becomes unavailable for any Data Manipulation Language (DML) operations such as INSERT, UPDATE, or DELETE. This is because the ONLINE keyword allows the index to remain accessible during the rebuild process. The NOLOGGING keyword, on the other hand, is unrelated to the lock status during an index rebuild and focuses on reducing the amount of redo log generation.
Answer C
Explanation: The syntax of the REBUILD command has many options such as TABLESPACE, ONLINE, and NOLOGGING. The discussion is narrowed down to ONLINE and NOLOGGING options. NOLOGGING disables redo generation only for the index rebuild; all subsequent DML against the index will generate redo as normal. Without the ONLINE keywordthe index is locked for DML, but not for SELECT. However, the rebuild still continues.
Réponse C