RDF/IMP and IMPX System Management Manual (RDF 1.3+)

Managing RDF
Compaq NonStop™ RDF/IMP and IMPX System Management Manual—522204-001
5-25
Performing Non-Shared Access DDL Operations
Performing Non-Shared Access DDL Operations
For DDL operations that do not include the WITH SHARED ACCESS option, you
can minimize outage for the primary system applications as follows:
1. Stop the applications that use the database being protected by RDF.
2. Stop TMF on the primary system.
3. Wait for RDF to stop.
4. Start TMF.
5. Start RDF with updating disabled.
6. Perform the DDL operations on the primary system.
7. Restart the applications.
8. Perform the same DDL operations on the backup system.
9. Issue an RDFCOM START UPDATE command.
Database administrators with a clear understanding of the underlying TMF auditing
issues might elect to skip some of these steps as long as the DDL operations and other
audited operations are performed in the correct sequence on the primary and backup
systems. For example, it is not absolutely necessary to stop TMF (and thus RDF), but it
is safest to do so. As long as application processing is stopped and the display from a
STATUS RDF command shows that the RTD time for every updater process is zero, the
DDL operations can be safely applied.
Performing Shared Access DDL Operations
DDL operations that include the WITH SHARED ACCESS option, and which are
performed on the primary system, generate a special Stop-RDF-Updaters audit record in
the MAT. As each updater on the backup system encounters that record in its image trail
file, that process logs an RDF message 733 and then shuts down. Check the RDF log to
ensure that all the updaters have generated a message 733. When all of the updaters have
done so, perform the same DDL operations on the backup system and then issue a
START UPDATE command.
If RDF aborts while the updaters are in the process of shutting down, check the RDF log
to see whether all of the updaters generated a message 733. If they did, then do as
follows:
1. Issue a START RDF, UPDATE OFF command on the primary system.
2. Perform the DDL operation(s) on the backup system.
Note. If you do not stop TMF on the primary system and wait for RDF to stop itself in response
to the TMFCOM STOP TMF command, make sure the RDF time delay (RTD) time for every
updater process is zero and that the updater processes have closed all database tables before
you start any DDL operation. To check the RTD times for the processes, issue a STATUS RDF
command. For this method to work, all applications protected by RDF must be shut down and
only the data base administrator manipulates the primary database.