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

Introducing RDF
Compaq NonStop™ RDF/IMP and IMPX System Management Manual—522204-001
1-19
Updater Processes
Partitioned Files, Alternate Key Files, and Indexes
Each updater is responsible for applying audit data to partitions corresponding to the
volume on the primary system that updater is protecting. Updates are applied directly to
the specific partition, regardless of whether it is a primary or secondary partition. RDF
does not use the file system for partition mapping.
Furthermore, because updates to the backup database are applied by logical
REDO/UNDO operations, alternate key files and SQL/MP indexes are not affected by an
update to a file or table. Alternate key files or SQL/MP indexes are updated
independently as a consequence of the individual audit records generated on the primary
system by TMF software.
File System Errors Involving Data Files
File system errors can occur when:
•
A file is created.
•
A file is opened.
•
A modify operation is performed on the file. Modify operations are those that the
updater might perform on an open file, such as updating the file (logical
REDO/UNDO) or altering the owner or security after the replication of a file
creation.
Errors encountered are reported in the EMS event log.
If an updater process encounters a file system error, it responds in either of the following
ways (depending upon the type of error that occurred):
•
Restarts and retries the operation again by reprocessing all database updates since
the last restart point. If the updater takes this course of action, it continues to do so
until the underlying problem goes away. This would be the action, for example, if an
updater process cannot create a data file on a backup volume because that volume is
protected by the Safeguard security management subsystem; in this case, the updater
logs error message 739, with an error 48, and restarts.
•
Skips the operation. This would be the action, for example, in response to an
error 010 (“file/record already exists”).
Note. You must be sure that volumes on the primary system containing alternate key files and
indexes are protected by RDF. It is not sufficient to protect just the associated data file or table
(particularly in the case of alternate keys). Likewise, if primary partitions reside on volumes
protected by RDF, you must ensure that the secondary partitions are also configured for
protection.