rs_subcmp Enhancement

In Replication Server 15.0.1, rs_subcmp uses a hash algorithm to improve its performance. Hash algorithm compresses the data in primary and replicated tables. The compressed data is then fetched by rs_subcmp.

Instead of taking the entire row of data during comparison between the primary table and replicated table, rs_subcmp now transfers only the compressed data of each data row from the primary or replicated tables, and then verifies or reconciles inconsistencies between them.

With the hash algorithm, the amount of data to be transferred from the primary and replicated tables to rs_subcmp is reduced, decreasing the total running time of rs_subcmp.

Note: Sybase suggests that you set the Adaptive Server Enterprise parameter default data cache to 128M or higher to get a better comparison performance.

Limitations

The enhanced rs_subcmp requires Adaptive Server Enterprise 15.0.2 or later and cannot handle case sensitive comparison. It also cannot handle text, unitext, or image datatypes and does not allow you to specify the precision for the float datatype (maximum precision is used).

Parent topic: New Features in Replication Server Version 15.0.1