Multiple choice

Which of the following actions is required to prevent row migration on a table?

  1. Decrease PCTUSED

  2. Increase PCTUSED

  3. Decrease PCTFREE

  4. Increase PCTFREE

  5. Increase database block size

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Row migration occurs when an updated row no longer fits in its original block and must move to another block, leaving a pointer behind. Increasing PCTFREE reserves more space in each block for future updates, allowing rows to grow in place. This prevents the need for rows to migrate to new blocks, maintaining performance and reducing chaining.