Reorganization is an important part of database maintenance. It helps save not only storage space, but also time.
Storage space can be saved by reducing the size of realms, reducing the size of the Database Key Translation Table (DBTT) of a record type and thereby reducing the maximum permissible number of records, and creating new set tables with a higher occupancy level.
Time can also be saved when accessing the database by reducing the number of overflow pages for hash areas, updating physical pointers which are in the form of probable position pointers (PPP), and creating new set tables with a different occupancy level.
Reorganization may become necessary when a realm has become too small, or more records of a record type are stored than originally planned.
Reorganization should be performed on a regular basis if record types which are specified with LOCATION MODE IS CALC and frequently updated are stored in the database as sort key tables, pointer arrays, chains, or lists. In such cases, updating may render the probable position pointers (PPP) in the tables incorrect. This would adversely affect access times to the records via the tables (see the “Database Operation“ manual).