Redis PFMERGE Command

Redis HyperLogLog

The Redis PFMERGE command merges multiple HyperLogLog into one HyperLogLog, and the estimated cardinality of the merged HyperLogLog is calculated by taking the union of all Given HyperLogLog for the union calculation.

Syntax

Basic syntax of the redis PFMERGE command is as follows:

PFMERGE destkey sourcekey [sourcekey ...]

Available Versions

>= 2.8.9

Return Value

Return OK.

Online Examples

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
redis>

Redis HyperLogLog