Schedule DBSPACE reorganizations and RELOADS during non-peak hours to avoid locking contention with other database users. If you schedule these kinds of jobs during peak hours, against heavy multiple user sessions, you may encounter lock contention when the system catalogs are updated. Running more than one DBSPACE reorganization or RELOAD simultaneously against a single database can also result in catalog contention.
Schedule a DBSPACE reorganization whenever the database statistics indicate that the DBSPACE needs it. For example, when indexes are no longer clustered or when considerable delete activity has occurred, leaving holes of deleted data on DBSPACE pages.
You can also use the DBSPACE Reorganization tool when you need a larger DBSPACE due to growth in the volume of data in the DBSPACE. In addition, use the tool to move DBSPACEs to less heavily occupied storage pools. Spreading the distribution of DBSPACEs across storage pools helps improve performance. Moving a DBSPACE can solve a short-on-storage problem and also eliminate the need to add a new dbextent to the database.
When you want to know the characteristics of the columns in a table, use the DBSPACE Reorganization tool's GENERATE DDL option. The generated DDL will show you how all of the objects in the DBSPACE are defined, what indexes exist, who has what authorizations, and what programs access what tables.