The following effects can be expected with the use of this facility:
- Effective reuse of free space
By reusing the free space of used pages, operations can be performed using a minimum amount of RDAREA space, thereby minimizing the frequency of database reorganization. If multiple tables and indexes are stored in the same RDAREA, the insertions and deletions for some tables can be combined, such that occupied area can be recovered.
- Recovery from an insufficient pages error for variable-length columns and BINARY type columns
Normally, if the no-split option is not specified, unused pages are allocated whenever a variable-length character column of at least 256 bytes is inserted or a BINARY type column that does not fit on one page is inserted. Even if used free pages are available, an error will result if an unused page cannot be allocated. If the free space reusage facility is being used, however, errors can be avoided because used free pages will be allocated if no unused free pages are available.
- Reduction in overhead during a search for free space on used pages
In the free page reuse mode, high-speed processing is possible due to the reduced overhead because the search start position is remembered and is used for the subsequent search.