RDF System Management Manual for J-series and H-series RVUs (RDF Update 13)

Figure 11 Unsynchronized Databases
Primary Backup
Database
T1
T4
T3
T6
T2
T5
MAT
T1
T4
T3
T6
T2
T5
Updater
Image File Database
T1
T4
T3
T2
T4
Making Changes to Database Structures
When you change the structure of a database on the primary system, you also need to change
the structure on the backup system.
NonStop SQL/MP or NonStop SQL/MX Databases
For NonStop SQL/MP or NonStop SQL/MX databases, changes you need to perform manually
on the backup system include:
• Catalog changes
• Results of DDL operations, including creating or altering tables and views
• Partition key changes
• Table purges
Catalog Changes
RDF regards NonStop SQL/MP and NonStop SQL/MX DDL operations like updates to SQL catalogs.
Although SQL catalogs are audited tables, RDF does not replicate catalog changes. The reason
for this is that catalog data has embedded data that contains system name and number information
as well as volume and subvolume information. When an operation on the primary system also
involves changing a catalog there, RDF cannot replicate that audited operation because it would
require that RDF transform the internal information within the data of the audit records, replacing
the system name and number information as well as perform volume mapping if required. The RDF
product does not perform data transformations, and therefore RDF does not create catalogs or
replicate catalog changes.
150 Maintaining the Databases