public class PTFValueCache
extends Object
Cache for storing aggregated values that were already calculated within a partition - used for
PTF functions. This cache can lead to performance improvement when PTFPartition would have to
calculate a particular aggregation for the same range again and again. The caching relies on the
fact that evaluators are deterministic in a sense that they'll give the same result for the same
range in the same partition (no matter for which row is the current target).