Backward-log recovery

During the backward-log recovery phase, Db2 completes recovery processing by reversing all changes performed for inflight and in-abort units of work.

At this point, all forward-log applies have been performed, and inflight, indoubt, and in-abort transactions are protected by locks. Any updates that cannot be externalized to the group buffer pool or to disk cause the affected pages to be added to the logical page list.

During backward-log recovery, you see messages similar to the following messages. (The phrase in parentheses is not part of the output.)

 DSNR006I @DB3ADB2 RESTART...COUNTS AFTER BACKWARD
 RECOVERY
 INFLIGHT=0, IN ABORT=0
 (End of backward-log recovery for member DB3A)
 DSNR002I @DB3ADB2 RESTART COMPLETED
 DSN9022I @DB3ADB2 DSNYASCP 'START DB2' NORMAL COMPLETION

The backward-log recovery messages for other members do not appear until those members are actually started. Backward-log recovery can occur in parallel for all the started members. No peer backward-log recovery exists; all members must be started to complete backward-log recovery and to release the locks held by inflight and in-abort transactions.