Oracle
1Z0-062 · Question #166
1Z0-062 Question #166: Real Exam Question with Answer & Explanation
The correct answer is B: Data blocks in an extent are logically contiguous but can be non-contiguous on disk.. An extent is a contiguous set of logically numbered data blocks within a single data file, and blocks in a newly allocated extent may have been used by prior objects before being freed.
Question
Which two statements are true about extents?
Options
- ABlocks belonging to an extent can be spread across multiple data files.
- BData blocks in an extent are logically contiguous but can be non-contiguous on disk.
- CThe blocks of a newly allocated extent, although free, may have been used before.
- DData blocks in an extent are automatically reclaimed for use by other objects in a tablespaee
Explanation
An extent is a contiguous set of logically numbered data blocks within a single data file, and blocks in a newly allocated extent may have been used by prior objects before being freed.
Common mistakes.
- A. An extent must reside entirely within a single data file because it is defined as a contiguous range of block addresses within one file; blocks cannot span across multiple data files.
- D. Blocks in an extent are not automatically reclaimed for other objects; they remain allocated to the owning segment until the segment is explicitly dropped, truncated, or the extent is manually deallocated.
Concept tested. Oracle extent structure and block allocation behavior
Reference. https://docs.oracle.com/en/database/oracle/oracle-database/19/cncpt/logical-storage-structures.html
Community Discussion
No community discussion yet for this question.