Checking the Database Files (SAP Library - Database Administration (Oracle) with SAPDBA)

Checking the Database Files

Use

Choose Check database to check for critical errors in the database that prevent further operations.

Procedure

The database is checked by analyzing the appropriate V$ tables. Because some of these tables are only updated when the database is restarted, SAPDBA differentiates between:

Online quick check: This check is performed with the database open. Any attempt to recover the database with SAPDBA is rejected, however, because the information obtained from this check is not necessarily current. As a result, if you have only performed the online short check, the Check database function is assigned the status not finished.

In addition you can use the SAPDBA menu option Archive mode ® Show complete archive history to determine initially which redo log files are necessary for a recovery, starting from the last backup. You can perform the online quick check at any time, in order to check the status of the control files, data files, and the online redo log files.

Offline safe check: If the database has not been closed yet, SAPDBA closes the database (with shutdown abort , if necessary). The database is then mounted. This guarantees that the information in the V$ tables is up-to-date. When the offline safe check is finished, and as long as it resulted in no errors, the database is opened again.

SAPDBA checks the condition of:

Data files (existence; Status: OK, RECOVERY; Status: ONLINE, OFFLINE)
Tablespaces (Status: ONLINE, OFFLINE; Status: BEGIN BACKUP, END BACKUP)
Control files (existence, validity if necessary)
Online redo log files (Existence; Status: OK, STALE, DAMAGED)

These checks do not find out, for example, whether table indexes are missing. To do this, use the database monitor of the R/3 System.

If the control files or redo log files are in a critical condition for the recovery, the database check ends. You cannot solve this type of error with SAPDBA. You need to take appropriate action with the right Oracle tools. For more information, see the Oracle documentation and Recovery with SVRMGR. Once you have removed the error, you can begin the database check again.

If defective data files are found, SAPDBA creates an internal list of the damaged files. Based on this list, SAPDBA determines the further recovery procedure.

Once the database check has been completed successfully (a safe check was performed, no errors found in the control or online redo log files), the Status is set to finished. If the check did not discover any errors in the database data files, all the other functions are assigned the status not needed, since no recovery measures are necessary. Otherwise, continue the recovery with the next menu item flagged as not finished.