Notes

In the following cases, the free space reusage facility will not function:
- When data is stored using the hash facility for hash row partitioning
- When data is stored in tables by means of data loading or by the database reorganization facility (pdrorg)
- When there is a user LOB RDAREA
When the free space reusage facility is used, page search processing is slower when free space due to deletions is not contiguous than when free space due to deletions is contiguous. In such a case, consider stopping the free space reusage facility or consider reorganizing the data with the database reorganization utility (pdrorg).
In the case of non-FIX tables, even if the free space reusage facility is used, the number of segments used might increase. If you perform an update such as the following, the number of segments used might increase even if the volume of additions and deletions of data remains the same:
If you perform repeated deletions after inserting (page length - 48) (row length + 2) data items and then updating data that would become longer than the row length (when NULL values are included) or data that would branch to another page
This case generates a full page, which you can release with the free page release utility (pdreclaim), in which case that page will no longer be able to store data. You can check whether such a page has been generated by using the database condition analysis utility (pddbst), in the value for Collect Prearranged Full Page.
Release the full page by executing one of the following:
- The free page release utility (pdreclaim)
- The database reorganization utility (pdrorg)
Even when searching is executed in the free page reuse mode, deleted space cannot be reused within the same transaction.
Even when the free space reusage facility is used, if you repeatedly perform UPDATE operations that change a non-NULL value to a NULL value, the number of segments allocated might exceed the actual data size. To prevent this, perform operations that use DELETE instead of performing an UPDATE operation on a NULL value.

14.5.7 Notes