CODEWITHSUNDEEP
redissetpipemultiset
raviop531
raviop531

Reputation: 31

Piped Set Operation in REDIS

Is it possible to compute multiset opeartion in redis using pipes i.e to say

(a union b union c) intersect (d union c) SUNION a b c SINTER d c

Upvotes: 2

Views: 879

Answers (2)

atomAltera
atomAltera

Reputation: 1781

No, but you can use trancastions (MULTI) 

MULTI
SUNIONSTORE abc a b c
SUNIONSTORE cd c d
SINTERSTORE i abc cd 
SMEMBERS i
DEL abc cd i
EXEC

p.s But it seems like you dont need to use c becouse after all its members will placed in i

Upvotes: 0

Mahn
Mahn

Reputation: 16585

No, because in a pipeline you only get results once the entire set of commands is sent (see documentation), ergo as you probably guessed you need to fetch the result of each nested operation in your example separately.

Something very similar however can be achieved using the scripting capability built in redis 2.6 with some lua, and it sounds like this could fit your bill:

EVAL "return redis.call('sinter', redis.call('sunion', 'a', redis.call('sunion', 'b', 'c')), redis.call('sunion', 'd', 'c'))"

The code above is a simplification and it's untested, but it should give you a rough idea of what's possible. More info on the documentation here.

Upvotes: 3

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