DEDB free space algorithm

The DEDB free space algorithm is used to free dependent overflow and independent overflow CIs.

This topic contains Diagnosis, Modification, and Tuning information.

When a dependent overflow CI becomes entirely empty, it becomes the CI pointed to by the current overflow pointer in the first dependent overflow CI, indicating that this is the first overflow CI to use for overflow space if the most desirable block is full. An independent overflow CI is owned by the UOW to which it was allocated until every segment stored in it has been removed. When the last segment in an independent overflow CI is deleted, the empty CI is made available for reuse. When the last segment in a dependent overflow CI is deleted, it can be reused as described at the beginning of this topic.

A dependent overflow or an independent overflow CI can be freed by reorganization or by segment deletion.