Counts number of distinct records, but only up to a preset amount - more efficient than an unbounded count
Merge maps of kind string -> set<string>
Essentially the same as MultiSet, but gets an Array for input.
Essentially the same as MultiSet, but gets an Array for input. There is an extra option to limit the number of keys (like CountDistinctUpTo)
Like Google's MultiSets.
Like Google's MultiSets. Aggregate function that creates a map of key to its count.