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

Online Database Synchronization
Compaq NonStop™ RDF/IMP and IMPX System Management Manual—522204-001
7-15
Partial Database Synchronization Considerations
1. Create an entire duplicate table on your backup system with a temporary name at a
temporary location (such as \BACKUP.$DATA.DUP.PART).
The alternative is to create the duplicate table on the primary system at a temporary
location (such as \PRIMARY.$DATA.DUP.PART).
If the table whose primary partition needs to be synchronized has indexes, do not
create indexes for the duplicate table. See step 2 for an explanation.
2. Use the SQLCI LOAD command with the PARTONLY and SHARED options to
load only the primary partition of the duplicate table. Note that you cannot use
PARTONLY with the LOAD command if your duplicate table has indexes.
Therefore, if you created your duplicate table with indexes, you must drop the
indexes.
3. When all loads have completed, issue the RDFCOM STOP SYNCH command.
4. If you created the duplicate tables on the primary system, then you must use the
BACKUP utility to put the entire duplicate tables with all partitions onto tape. Note
that because you only loaded the one partition, all other partitions of this duplicate
table are empty.
If you created the duplicate table directly on the backup system, skip this step.
5. If you created the duplicate table on the primary system, then you must use the
RESTORE utility to put the entire duplicate table with all its partitions onto disk on
the backup system. Note that you must use MAP NAMES to correct the system
name. Thus, $DATA.DUP.PART is now on the backup system.
If you created the duplicate table directly on the backup system, skip this step.
6. Rename the original table on the backup system whose primary partition is being
synchronized to a temporary name using the SQLCI ALTER TABLE command
($DATA.TEST.PART becomes $DATA.TEMP.PART).
7. Rename the duplicate table on the backup system to the name of the original table
whose partition is being synchronized using the SQLCI ALTER TABLE command
($DATA.DUP.PART becomes $DATA.TEST.PART).
8. Use the BACKUP utility with the PARTONLY option to back up just the partition
you need synchronized to tape (the primary partition, in this example). Remember
that the duplicate table now has the name of the original table. Thus, you now have
on tape the loaded partition that you need to synchronize. Because the partition has
the correct name, you will not need to use MAP NAMES when you eventually
restore it.
9. Rename the duplicate table back to its original duplicate table name ($DATA.
TEST.PART becomes $DATA.DUP.PART).
10. Use SQLCI to drop the duplicate table. Note that by renaming the duplicate table
back to its original name before dropping it, you can preserve whatever indexes exist
on the backup system that are associated with the table being synchronized.