RDF System Management Manual for J-series and H-series RVUs (RDF 1.10)

Replicating Database Operations
Database administrators preparing to work with RDF should be aware of considerations concerning:
• NonStop SQL Data Definition Language (DDL) operations
• NonStop SQL DDL operations with Shared Access
• Enscribe file-label modifications
• Purge operations
• Partitioned files
• Temporary disk files
NonStop SQL DDL Operations
Although RDF replicates NonStop SQL Data Manipulation Language (DML) operations, it does not
replicate NonStop SQL Data Definition Language (DDL) operations except for PURGEDATA.
Excluding PURGEDATA, the database administrator needs to perform all other DDL operations
(such as CREATE TABLE or CREATE INDEX) manually on the backup system as well as on the
primary system.
User programs should not create audited NonStop SQL tables and write to them without coordinating
table creation on the primary system with table creation on the backup system.
Recommended procedures for performing NonStop SQL DDL operations in an RDF environment
are described in “NonStop SQL/MP or NonStop SQL/MX Databases” (page 151).
Enscribe File-Label Modifications
In general, RDF does not replicate Enscribe file-label modifications.
File-label modifications in Enscribe are similar to DDL operations in NonStop SQL products, in that
the modifications do not manipulate the file itself. Instead, file-label modifications alter attributes
of the file, such as the file code, the security, the extent size, and the audit setting.
The only file-label modifications that RDF replicates are:
To create an audited Enscribe fileCREATE
To increase the number of extents for an audited Enscribe
file
ALTER MAXEXTENTS
To purge data from an audited Enscribe filePURGEDATA
To purge an Enscribe file (if REPLICATEPURGE is enabled)PURGE
Purge Operations
The two kinds of purge operations are PURGEDATA and PURGE. RDF replicates PURGEDATA
operations for NonStop SQL tables and Enscribe files. RDF replicates PURGE operations for Enscribe
files if REPLICATEPURGE is set on.
Partitioned Files
All partitions of a partitioned Enscribe file or NonStop SQL table or index must reside on volumes
protected by RDF, or none should. Corresponding partitions on each system must have the same
key values.
CAUTION: For partitioned files, it is essential that the partial key value for Enscribe files or first
key value for NonStop SQL tables on the backup system exactly match those on the primary system.
This is the RDF database administrator’s responsibility.
If you are using RDF to replicate the creation of partitioned files and an RDF takeover operation
occurs in the midst of a set of creations, some partitions might have been created while others
were not, because each partition of a partitioned file is created independently.
Preparing Software and Database Files for RDF Operations 59