Owner manual

Configuring SDR
HP NonStop SQL DDL Replicator User’s Guide—545799-005
3-3
Configuring SDR Capture
The global settings are changed using the ALTER command and reset to their default
with the RESET command.
To issue the ALTER and RESET commands you must be a SUPER user and have
update access to the REGISTRY table in the SDRSYSDB subvolume.
Configuring SDR Capture
Configuring SDR Replication
Configuring SDR Capture
The following paragraphs describe global settings that control DDL capture:
Enabling and Disabling SDR
Requiring DDL Capture
Retaining Captured DDL
Handling DDL Operations performed under a User Transactions
Enabling and Disabling SDR
It is highly recommend to leave the SDR monitor running at all times. If it becomes
necessary to disable DDL capture for any reason, it can be done by setting the
DDLCAPTURE global parameter to DISABLED.
Requiring DDL Capture
When a DDL operation is performed on a SQL table, operational problems could
prevent SDR from capturing and preserving the DDL statement for replication. For
example, if the SDR monitor is stopped, DDL capture is impossible, or if a security
error prevents SDR from accessing its files, then the statement cannot be stored. The
capture problem on the primary table might cause the backup table to become
inconsistent or unusable.
By default, SDR allows the DDL operation to be performed on the primary table, even if
it cannot be captured for replication. But you can choose to make the DDL replication
mandatory by not allowing the DDL operation to succeed on the primary table if it
cannot be captured by SDR. This is done by setting the global parameter
DDLCAPTURE to REQUIRED (instead of the default ENABLED).
Obviously, mandatory DDL replication could have an adverse affect on applications
that perform DDL. But, if all DDL is performed using ad hoc SQLCI commands, it is a
useful safeguard against accidental corruption of the backup database.
ALTER [GLOBAL] parameter-and-value