Rolling Forward from Backup

If the audit updates configuration option has been used to switch transaction auditing on for a database, then the software maintains disk files of all committed transactions. The audit files are named zimtrans.n, where n is an integer (i.e., 0, 1, 2, 3, etc.). The files are kept in the disk directory specified by the audit path configuration option; or, if an audit path is not specified, in the database directory.

Note: All users must have audit updates set to yes if the database is to be properly audited. Universal auditing is guaranteed by setting audit updates to yes in the database configuration file.

In applications that maintain transaction audit files, use the Transaction Recovery (ZIMRCVR) administrative utility to "roll forward" a backup copy of the database.

The procedure for reverting to a backup copy of the database is operating system-specific.

Use this general procedure for recovering updates from transaction files:

  1. Revert to the most recent backup copy of all database files, but not the transaction files (zimtrans.0, zimtrans.1, etc.).
  2. At the operating system level, execute the ZIMRCVR utility.

OR

At the Administrative Utilities window, execute the Transaction Recovery icon.

Transaction Recovery (ZIMRCVR) applies all current transaction files to the backup database files, thus rolling the database forward to the end of the last complete transaction.

If  the most recent backup copy of the database is also corrupt, recovery can still be possible. However, such a recovery is only possible if an earlier backup copy of the database exists. In this case, use this general procedure:

  1. Make a backup copy of the current transaction files.
  2. Revert to the transaction files from the most recent backup copy of the entire database.
  3. Revert to the database files (but not the transaction files) from the next-most-recent backup copy of the entire database.
  4. Execute Transaction Recovery (ZIMRCVR).
  5. Bring back the transaction files that you saved in step 1.
  6. Execute Transaction Recovery (ZIMRCVR) again.

Use this technique to go as far back in time as backups of the entire database (including transaction files) exist. Note, however, that the procedure works only if the transaction files in a given backup represent all the updates carried out since the previous backup.