When you specify that you want to use a replication definition for replicating into a standby database:
Replication Server optimizes updates and deletes by using the primary key defined in the replication definition to generate the where clause.
You can specify whether Replication Server uses the replication definition’s replicate minimal columns setting for replicating into the standby database. This setting indicates whether updates replace the values for all columns or only the columns with changed values.
You can specify whether Replication Server replicates all of a table’s columns or all of a stored procedure’s parameters to the standby database or only those columns or parameters listed in the table or function replication definition.
To create a replication definition just for replicating into the standby database, use the send standby clause in the create replication definition command. The replication definition’s primary key and replicate minimal columns setting will be used in replicating into the standby database.
Refer to Chapter 3, “Replication Server Commands,” in the Replication Server Reference Manual for detailed information about using create replication definition command.
Replication Server generates a where clause to specify target rows for updates and deletes.
If a replication definition for a table is marked with the send standby clause, the generated where clause contains only the columns listed in the primary key clause of the create replication definition command.
If there are replication definitions for a table but none are marked with the send standby clause, the generated where clause contains the columns listed in the union of the primary key clauses of all of the replication definitions.
If there is no replication definition for a table, the generated where clause includes all columns in the table except text, unitext, image, rawobject, rawobject in row, timestamp, and sensitivity columns.
If you create a replication definition for replicating into a standby database, you can take advantage of another replication system performance optimization, the minimal columns setting.
When you use the replicate minimal columns clause, replicated update and delete transactions include only the required columns. Values for unchanged columns can be omitted from update commands. Omitting the unnecessary columns reduces the size of messages delivered through the replication system and requires Adaptive Server to do less work.
If you are not using replication definitions for replicating into the standby, you can still attain this performance benefit.
Minimal column replication occurs automatically if you have no replication definitions for a table or if you have replication definitions for a table but do not use one for replicating into the standby database.
If you create a replication definition for replicating into a standby database, you can specify which set of columns to replicate:
Specify send standby or send standby all columns to replicate all the columns in the table into the standby database.
Specify send standby replication definition columns to replicate only the replication definition’s columns into the standby database.
Refer to Chapter 3, “Replication Server Commands,” in the Replication Server Reference Manual for more information about using the send standby clause with the create replication definition command.
If you create a function replication definition, you can specify which set of parameters to replicate:
Specify send standby all parameters (or omit the all parameters clause) to replicate all the parameters for the stored procedure into the standby database.
Specify send standby replication definition parameters to replicate only the replication definition’s parameters into the standby database.
If a replicated stored procedure has no function replication definition, when the stored procedure is executed, Replication Server replicates all of its parameters from the active database into the standby database. You can create only one function replication definition per replicated stored procedure.
See Chapter 3, “Replication Server Commands,” in the Replication Server Reference Manual for more information about using the send standby clause with the create applied/request function replication definition command.
