Merge Replication Performance Issues, Enumerating Inserts And Updates For Articles...generations And Batches

We have a SQLServer 2005 Enterprise merge replication publication with SQL Mobile 3.0 subscribers (Windows Mobile 5.0 and 6.0). We do not use pre-computed partitions due to trigger performance issues with an SSIS/ETL application that supplies data to the merge database. We do use the "Optimize" (=true) option, though we have tried this both ways with no significant differences. We use filters and joins for each worker ID (as HOST_ID) from the subscriptions.

The sync times become increasingly worse after we run the snapshot and bring the publication online. I have tried rerunning the snapshots, this helps little, as it often behaves like the subscription was set to reinitialize and forces a big sync (reload of all data) to the subscriber. We have tried much of the obvious (e.g., flattening filters and joins, adding indexes, etc.).

When users are synchronizing, we watch replication monitor and notice that a lot of time is spent processing "enumerating inserts and updates for article [any article]", especially processing the many generations and batches. This is true for any follow-up syncs after the 1st big sync (initializing the subscription).

I read several posts regarding the batches and generations of changes, and decided to try increasing the €œDownloadGenerationsPerBatch€?. I tried adding this parameter to the snapshot agent job, and the job fails each time with a vague message, even with the default value of 100. How do you change this parameter for SQLServer 2005 Enterprise?

Any suggestions?

Thanks in advance,
Matt