Returns the approximated cardinality computed by the HyperLogLog data structure stored at the specified key.
When called with a single key, returns the approximated cardinality computed by the HyperLogLog data structure stored at the specified variable, which is 0 if the variable does not exist.
When called with multiple keys, returns the approximated cardinality of the union of the HyperLogLogs passed, by internally merging the HyperLogLogs stored at the provided keys into a temporary HyperLogLog.
scope string keys
Jan Krüger, Sönke Ludwig, Michael Eisendle, Etienne Cimon
© 2012-2016 RejectedSoftware e.K.
Subject to the terms of the MIT license, as written in the included LICENSE.txt file.