Frequency Sketches

Frequency estimation involves determining how often an item has been seen in a stream. The library currently offers two types of sketches for frequency estimation, one of which has two closely-related variants.

  • frequent_items_sketch: Identifies the Top K or heavy hitters in a stream, those items whose weight is above a certain percentage of the entire stream. Does not necessarily provide an estimate for most items outside the heavy hitters.

  • frequent_strings_sketch: Like the items version but containing snly strings (an implementation from before the library handled generic objects).

  • count_min_sketch: Provides an estimate for any item, regardless of relative weight, but does not maintain a list of the heaviest items.