RDF/IMP, IMPX, and ZLT System Management Manual

NonStop SQL/MX and RDF
HP NonStop RDF/IMP, IMPX, and ZLT System Management Manual—524388-002
15-8
Online Database Synchronization With NonStop
SQL/MX Objects
Online Database Synchronization With
NonStop SQL/MX Objects
The principles of protocol for online database synchronization with NonStop SQL/MX
objects are the same as for Enscribe and NonStop SQL/MP objects. That is, you follow
the guidelines for the RDF online database-synchronization protocol. The only
difference is how the fuzzy copy is obtained. The following discussions focus on the
two options for getting the fuzzy copy: creating a fuzzy copy on the primary system or
creating the fuzzy copy on the backup system.
Creating the Fuzzy Copy on the Primary System
The advantage of this method is that in creating and populating the fuzzy copy on the
primary system you achieve better performance than by creating and populating the
fuzzy copy over the network. Once created and populated, you use
BACKUP/RESTORE to move the fuzzy copy to the backup system. The disadvantage
of this method is that it requires disk space on the primary system to store a second
copy of your NonStop SQL/MX database.
To create the fuzzy copy on the primary system, perform the following steps.
1. Create a temporary catalog on your primary system to correspond to your regular
catalog on your primary system whose objects you want RDF to replicate.
CREATE CATALOG <catalog_name> LOCATION <optional_guardian_location>;
2. Create a temporary schema for your temporary catalog. Follow the instructions
given in Step 2 of the procedure Creating a NonStop SQL/MX Backup Database
From an Existing Primary Database, above (but follow those instructions on your
primary system instead of on the backup system). Note, the name of the
temporary schema must be identical to the name of the schema whose objects you
want replicated. You must also ensure that the subvolume name for the temporary
schema is identical to that of the schema whose objects you want replicated.
3. Create temporary objects in your temporary schema. Follow the guidelines outlined
in Creating a NonStop SQL/MX Backup Database From an Existing Primary
Database above, except that you must create these temporary objects on the
primary system and on different volumes from those used for your primary objects.
You can use the use the MXGNAMES utility as described under Step 4 of Creating
a NonStop SQL/MX Backup Database From an Existing Primary Database, above,
to generate the LOCATION clauses for the temporary objects, modifying the
volume names as necessary and using the primary node name for the -node
option. Alternatively, you can use the SHOWDDL command to obtain the fully
qualified filenames of the objects you want replicated and specify the same
Guardian subvol.filenames in the corresponding LOCATION clauses when creating
the temporary objects.