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

Online Database Synchronization
Compaq NonStop™ RDF/IMP and IMPX System Management Manual—522204-001
7-4
Database Considerations When Synchronizing
Entire Databases
CREATE/LOAD Issues
The LOAD command only works on tables and files that are nonaudited. If you create
the empty duplicate tables and files as audited entities, you must then use FUP ALTER
commands to turn off their audit attributes before you can load them.
When you create empty Enscribe files on the primary system, you should make them
nonaudited. This is particularly important if you create them on volumes protected by
RDF. If you create them as audited files on protected database volumes, the updaters
also create them on the backup system. You then must purge the files on the backup
system before copying the loaded files from the primary system.
For information about the SQLCI LOAD or FUP LOAD commands, refer to the
Compaq NonStop™ SQL/MP Reference Manual or the File Utility Program (FUP)
Reference Manual, respectively. The following information is general in nature and is
not intended as a substitute for the information contained in those two manuals.
Enscribe Files
•
Key-sequenced Files. To improve the performance of the load operations, specify
the SORTED option for key-sequenced files.
•
Relative Files. To ensure complete consistency with the source files, specify the
NO COMPACT option for relative files.
•
Entry-sequenced Files. There is currently no reliable mechanism to synchronize
entry-sequenced files online. Entry-sequenced files should be synchronized offline.
•
Unstructured Files. There is currently no reliable mechanism to synchronize
unstructured files online. Unstructured files should be synchronized offline.
•
Partitioned Files. For partitioned files, you can initiate the load operation with a
single command by executing the LOAD command against the primary partition.
•
Alternate Key Files. You should execute LOAD commands against all alternate
key files.
SQL Tables
•
Key-sequenced Tables. To improve the performance of the load operations
significantly, specify the SORTED option.
•
Relative Tables. To ensure complete consistency with the source files, specify the
NO COMPACT option.
•
Entry-sequenced Tables. There is currently no reliable mechanism to synchronize
entry-sequenced tables online. Entry-sequenced tables should be synchronized
offline.
•
Partitioned Tables. You can initiate the load operation with a single command by
executing the LOAD command against the primary partition.
Note. Because the SQLCI LOAD operation generates new SYSKEY values in the backup
table, key-sequenced tables containing SYSKEYs cannot be synchronized online.