Replication Server includes High Volume Adaptive Replication (HVAR) to achieve better performance compared to the current continuous replication mode when replicating into Sybase IQ replicate database with identical database schema.
In the continuous replication mode, Replication Server sends each logged change to the replicate database according to the primary database log-order. HVAR achieves better performance with:
Compilation – rearranges replicate data, by clustering it by each table, and each insert, update, and delete operation, and then compiling the operations into net-row operations.
Bulk apply – applies the net result of the compilation operations in bulk using the most efficient bulk interface for the net result. Replication Server uses an in-memory net-change database to store the net row changes which it applies to the replicate database.
HVAR tries to group as many compilable transactions as possible together, compiles the transactions in the group into a net change, and then uses the bulk interface in the replicate database to apply the net changes to the replicate database.
Instead of sending every logged operation, compilation removes the intermediate insert, update, or update operations in a group of operations and sends only the final compiled state of a replicated transaction. Depending on the transaction profile, this generally means a much smaller amount of data is processed.
See “HVAR compilation and bulk apply,” for more information on HVAR processing.
