PFMERGE

PFMERGE destkey sourcekey [sourcekey ...]

#Example

redis> PFADD hll1 foo bar zap a
(integer) 1
redis> PFADD hll2 a b c foo
(integer) 1
redis> PFMERGE hll3 hll1 hll2
"OK"
redis> PFCOUNT hll3
(integer) 6

Merge N different HyperLogLogs into a single one.