DB2 Server for VSE & VM: Data Restore Guide

Overview

Unload and load procedures are used when you want to reorganize the data, import or export data, or back up or restore part of the database.

If you used unload procedures previously, you could not apply a log. That is, you could not automatically track and apply any changes that were made to the data after the unload was taken. However, there is now the possibility to RELOAD a specific table from a Data Restore archive or DB2 archive and apply the log.

The main reasons to unload data are to:

• Reorganize a table
  • when the indexes become unclustered
  • when the table specifications need changes
  • when the dbspace specifications need changes
• Copy a complete table or a part of it from one database to another to create a test environment.
• Use the unloaded data as input to another relational database or even to a non-relational database, for example a spreadsheet or reporting application.
• Back up critical tables between archives or log archives:
  • If something goes wrong with your database, it would be faster to restart the environment without having to restore all data.
  • If the database manager cannot be restarted at all, you would at least have a recent copy of important tables.

  But note that no log can be applied and thus changes to those tables are not reflected. These table backups are now no longer necessary when using the Data Restore feature.