DB2 Server for VSE: System Administration

Preparing for Database Regeneration

If the SYS0001 dbspace ever becomes too small to hold the catalog tables, or if the contents of the directory data set or a dbextent data set are damaged or destroyed and you do not have archives to restore them, the database can no longer serve your needs and must be regenerated.

The size and complexity of the regeneration task depends on the size and complexity of the database. This task includes:

• Regenerating the database, including any dbspaces, dbextents, and VM minidisks that may have been added since the previous generation
• Using the DBS utility to unload and reload all the data in the database, including the ISQL routines and the ISQL stored queries.
• Repreprocessing all application program packages
• Reestablishing the entire authority scheme
• Recreating all views and indexes.

One way to simplify this task is to keep a record of the various types of information you would need to reestablish the operating environment that existed in the previous database. In particular:

• Keep all the ACQUIRE DBSPACE, CREATE TABLE, ALTER TABLE, GRANT, CREATE INDEX, CREATE VIEW, and CREATE SYNONYM statements for the database in DBS utility job streams. These job streams can be run easily on the regenerated database.

  Note:

  If these statements are not kept, you can reconstruct them from information available in the system catalog tables. However, this could take a long time for a large production database.

• Keep all the VSAM Access Method Services statements used to define the VSAM data sets for the database, both for initial generation and for later ADD DBEXTENT operations. Also keep the statements used for any log reconfigurations. These statements can be used in one job to redefine the VSAM data sets.
• Keep all the input control statements for any ADD DBSPACE or ADD DBEXTENT operations. These statements can be used as input to the job that regenerates the database.
• Keep the database job control (DLBL, TLBL, and LIBDEF statements) up to date in a cataloged procedure. This procedure can be used by the job that regenerates the database.
• Keep the jobs used to preprocess each application program so that they can be run on the regenerated database (as separate jobs).