Saving and restoring indexes in the distributed relational database environment

 

Restoring an SQL index can be faster than rebuilding it. Although times vary depending on a number of factors, rebuilding a database index takes approximately one minute for every 10 000 rows.

After restoring the index, the table might need to be brought up to date by applying the latest journal changes (depending on whether journaling is active). Even with this additional recovery time, you might find it faster to restore indexes rather than to rebuild them.

The system ensures the integrity of an index before you can use it. If the system determines that the index is unusable, the system attempts to recover it. You can control when an index will be recovered. If the system ends abnormally, during the next IPL the system automatically lists those tables requiring index or view recovery. You can decide whether to rebuild the index or to attempt to recover it at one of the following times:

• During the IPL

• After the IPL

• When the table is first used

 

Parent topic:

Save and restore processing for a distributed relational database

 

Related concepts

Backup and recovery