Virtual DataPort includes a series of memory settings that allow customizing certain aspects of the Execution Engine. The following sections explain how they work and includes some tips to use them effectively.
Usually, you do not need to change the default memory settings, with the exception of the “Limit Query Memory Usage” parameters (see section Limit the Maximum Amount of Memory of a Query),
Memory usage considerations are only of interest for queries in which the Virtual DataPort server processes a large number of rows and perform several operation over them. In many cases this can be avoided by maximizing push down of queries to the data sources, so rows are filtered and/or aggregated at the data sources and Virtual DataPort only has to combine a smaller number of rows. To maximize push-down, Denodo applies many automatic optimizations that in some cases, involve redesigning queries.