Use MaxSummaries to limit the memory usage of the data store. Memory consumption increases linearly with each summary that is cached in the multidimensional array. MaxSummaries prevents too many summaries to be cached at once. 

When the ActiveFlag property of a summary is diActive, the summary is always added to the cache. When the ActiveFlag property is diAsNeeded, it can be added only if it does not cause the number of active summaries to exceed MaxSummaries. The data store swaps in as-needed summaries when they are chosen as the current summary, making room, if necessary, by swapping out other as-needed summaries. 

MaxCells 

MaxDimensions 

SummaryCount 

ActiveFlag