Data Verification Before Backup

As the DBA, you must know that the data in your database is good (can be accessed) before backing it up. This can assure that a successful recovery can be made if it becomes necessary to restore the database from the backup copy.

Methods of Verifying Data Accessibility

One method of verifying the accessibility of your tables is to write a script that automatically checks each of the tables and system catalogs in your database.

Otherwise, you can use one of the following suggested methods in VDBA:

• Modify system tables to predetermined storage structures using the System Modification dialog.
• Modify user table storage structures using the Modify Table Structure dialog.
• Use any procedure that affects all the rows that are being backed up in each table. (For example, select all the rows from the tables using an SQL Scratchpad window.)

  If rows in a table are not accessible, you receive an error message. If this happens, restore the table from an earlier checkpoint before doing a new backup.

• Check the integrity of specific tables using the Verify Database dialog. (For each table, specify report for Mode, table for Operation, and a table name.)

For the detailed steps for performing these procedures, see online help.

You can also accomplish these tasks using the sysmod, modify, select, and verifydb commands. For more information, see the Command Reference Guide.