CHAPTER 11 Backup and Data Recovery

A second automatic checkpoint occurs at the end of backup. Any data that is committed while the backup is in progress is included in any subsequent backups. However, if a failure occurs between the first and second checkpoints, any work that occurred after the first checkpoint cannot be restored.

Adaptive Server IQ backs up only those database blocks actually in use at the time of backup. Free blocks are not backed up.

Adaptive Server IQ backs up the database files and the Catalog information that pertains to the IQ database to which you are connected. It does not back up the transaction log file. It does not use the transaction log to restore the database.

If your database needs a rollback or is missing files, the backup fails.

The transaction log in backup, restore, and recovery

Adaptive Server IQ uses the transaction log file during recovery from a system failure. It does not use the transaction log to restore an IQ database, to recover committed IQ transactions, or to restore the Catalog Store for an Adaptive Server IQ database. However, the restore program does check for the existence of the transaction log:

For a full restore, the transaction log must not exist. You must delete this file before starting a full restore.

For an incremental restore, the transaction log must exist. You must not delete this file or you will not be able to do an incremental restore.

Note Adaptive Server Anywhere databases use the transaction log and other logs differently. If you are recovering such a database, you need its transaction log file, and BACKUP retains it for you. See the Adaptive Server Anywhere User’s Guide for details. Also, if you have data (other than the system tables) in your Catalog store, transactions for that data can only be recovered if they were written to disk before a failure.

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