The database replication module querybuilder can be improved by adding
to the queries.
Edit 1: As Erics says this has disadvantages. An alternative is to make views in the replicated database which return only data that is recently changed. Take a reasonable timeframe to avoid missing update, like 2 weeks if you replicate daily. Use this views instead of the original tables as you use now. This only works when is it NOT a full replication including deleting of data in the Mendix database.