Redis Pfcount Command
The Redis Pfcount command returns the cardinality estimate of a given HyperLogLog.
Syntax
The basic syntax of the Redis Pfcount command is as follows:
redis 127.0.0.1:6379> PFCOUNT key [key ...]
Available Versions
>= 2.8.9
Return Value
Integer. Returns the cardinality value of the given HyperLogLog. If multiple HyperLogLogs are given, returns the sum of the cardinality estimates.
Example
redis 127.0.0.1:6379> PFADD hll foo bar zap (integer) 1 redis 127.0.0.1:6379> PFADD hll zap zap zap (integer) 0 redis 127.0.0.1:6379> PFADD hll foo bar (integer) 0 redis 127.0.0.1:6379> PFCOUNT hll (integer) 3 redis 127.0.0.1:6379> PFADD some-other-hll 1 2 3 (integer) 1 redis 127.0.0.1:6379> PFCOUNT hll some-other-hll (integer) 6 redis>
Other Extensions