When the Merge Agent sends updates between the Publisher and Subscriber , it does so in the form of batches. Under normal circumstances, this default value is appropriate. But if the published table experiences frequent updates and there are a large numbers of rows in a single transaction, then increasing the size of the batch can boost performance. There are two settings in the Merge Agent profile where you can change the number of generations sent during a batch, the DownloadGenerationsPerBatch and the UploadGenerationsPerBatch. Merge replication offers both static and dynamic filters.
Static filters use a literal value to include or exclude data in a subscription.
Dynamic filters, on the other hand, use an intrinsic function instead. For best performance, use static instead of dynamic filters , as SQL Server requires more overhead to process them than static filters. If you are using transactional replication , you may want to monitor the latency that it takes the Log Reader to move transactions from a database's transaction log until it puts it in the distribution database, and to also monitor the latency it takes the Distributor Agent to move transactions from the distribution database to the Subscriber database. The total of these two figures is the amount of time it takes a transaction to get from the publication database to the subscriber database. If you see a significant increase in the latency for either of these processes, this should be a signal to you to find out what new or different has happened to cause the increased latency.