Reduce 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. You can control when to have the access path recovered.

Access path recovery can take a long time, especially if you have large access paths or many access paths to be rebuilt. You can reduce this 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.

• Save access paths
  You can reduce the recovery time of access paths by saving access paths. The access path (ACCPTH) parameter on the Save Changed Objects (SAVCHGOBJ), Save Library (SAVLIB), and Save Object (SAVOBJ) commands allows you to save access paths.
• Restore access paths
  The system has the ability to restore access paths and it usually restores an access path faster than it rebuilds it.
• Journal access paths
  Journaling access paths can significantly reduce recovery time by reducing the number of access paths that need to be rebuilt after an abnormal system end. It is recommended 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.
• Rebuild 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.