ZUNION numkeys key [key ...] [WEIGHTS weight [weight ...]] [AGGREGATE SUM|MIN|MAX] [WITHSCORES]

Available since 6.2.0.

Time complexity: O(N)+O(M*log(M)) with N being the sum of the sizes of the input sorted sets, and M being the number of elements in the resulting sorted set.

This command is similar to ZUNIONSTORE, but instead of storing the resulting sorted set, it is returned to the client.

For a description of the WEIGHTS and AGGREGATE options, see ZUNIONSTORE.

*Return value

Array reply: the result of union (optionally with their scores, in case the WITHSCORES option is given).

*Examples

redis>  ZADD zset1 1 "one" 
(integer) 1
redis>  ZADD zset1 2 "two" 
(integer) 1
redis>  ZADD zset2 1 "one" 
(integer) 1
redis>  ZADD zset2 2 "two" 
(integer) 1
redis>  ZADD zset2 3 "three" 
(integer) 1
redis>  ZUNION 2 zset1 zset2 
1) "one"
2) "three"
3) "two"
redis>  ZUNION 2 zset1 zset2 WITHSCORES 
1) "one"
2) "2"
3) "three"
4) "3"
5) "two"
6) "4"
redis>