Oracle Database 12c: Installation and Administration — Question 153

You want to reduce fragmentation and reclaim unused space for the SALES table but not its dependent objects. During this operation, you want to ensure the following:
- Long-running queries are not affected.
- No extra space is used.
- Data manipulation language (DML) operations on the table succeed at all times throughout the process.
- Unused space is reclaimed both above and below the high water mark.
Which ALTER TABLE option would you recommend?

Answer options

• A. DEALLOCATE UNUSED
• B. SHRINK SPACE CASCADE
• C. SHRINK SPACE COMPACT
• D. ROW STORE COMPRESS BASIC

Correct answer: C

Explanation

The correct answer is C, SHRINK SPACE COMPACT, which allows for reclaiming unused space while ensuring that DML operations can continue without interruption. Options A (DEALLOCATE UNUSED) would not meet the requirement of not affecting long-running queries, while B (SHRINK SPACE CASCADE) would affect dependent objects, and D (ROW STORE COMPRESS BASIC) does not specifically address the space reclamation needs outlined.