Reducing time in access path recovery

 

The system ensures the integrity of an access path before you can use it. If the system determines that the access path is unusable, the system attempts to recover it. Access path recovery might take a long time; however, you can reduce the recovery time in several ways.

Journaling access paths is often faster than rebuilding access paths. With the System-managed access path protection (SMAPP) support, you do not have to use the journaling commands, such as the Start Journal Access Path (STRJRNAP) command, to get the benefits of access path journaling. SMAPP support recovers access paths after an abnormal system end rather than rebuilding them during IPL.

• Saving access paths
  You can reduce the time of access path recovery by saving access paths. To save access paths, you can use the access path (ACCPTH) parameter on the Save Changed Objects (SAVCHGOBJ), Save Library (SAVLIB), and Save Object (SAVOBJ) commands.

• Restoring access paths
  The system has the ability to restore access paths. It usually restores an access path faster than it rebuilds an access path.

• Journaling access paths
  Journaling access paths can reduce recovery time by reducing the number of access paths that need to be rebuilt after an abnormal system end. It is suggested that you journal access paths because larger access paths require more time to rebuild.

• System-managed access-path protection
  System-managed access-path protection (SMAPP) provides automatic protection for access paths. With SMAPP support, you do not have to use the journaling commands, such as the Start Journal Access Path (STRJRNAP) command, to get the benefits of access path journaling.

• Rebuilding access paths
  Rebuilding a database access path might take as much as one minute for every 10 000 records. But some factors might affect the time estimate for rebuilding access paths.

 

Parent topic:

Recovering and restoring your database