By sending data for only the columns specified in the replication definition, network traffic is reduced, which may improve performance.
The Replication Agent use_rssd configuration parameter controls whether the Replication Agent sends Log Transfer Language (LTL) that contains only the columns specified in a replication definition or all of the columns in the primary table, as follows:
When the value of the use_rssd parameter is false, the Replication Agent sends LTL with data for all of the columns in the primary table.
When the value of the use_rssd parameter is true, the Replication Agent sends LTL with data for only the columns specified in the replication definition for each primary table.
In addition, column names and parameter names are removed from the LTL because the Replication Agent can send information in the order identified by the replication definition. The LTL minimal columns and structured tokens options are also available when the value of the use_rssd parameter is true. See the Replication Agent Administration Guide.
To alter replication definitions, see the Replication Server Administration Guide Volume 1 > Manage Replicated Tables > Modify Replication Definitions > Altering Replication Definitions > Replication Definition Change Request Process.