[Feature request] Sorted Set and Set intersections

I would like to be able to do intersections on sets and a score- or 
rank-limited sorted sets. 

Assume that we have some sorted sets:

* users:activity {timestamp, userid}
* users:age {age, userid}

And some sets

* users:male {userid}

It would be nice to be able to do something like (syntax not supposed to be 
redis):

    users:activity by rank 0 to 100 INTERSECT users:age by score <18> to +inf  INTERSECT users:male

Not sure how this could be expressed without changing the current syntax too 
much, perhaps using an extension to ZRANGE a la:

    ZSTORERANGE dstkey key start end   #Store a sorted set range (by rank) as a set
    ZSTORERANGEBYSCORE dstkey key min max #Store a sorted set range (by score) as a set

That would mean that I could do my intersection as:

    INCR i
    ZSTORERANGE tmp:<i>:activity users:activity 0 100
    ZSTORERANGEBYSCORE tmp:<i>:age users:age 18 +inf
    SINTER tmp:<i>:activity tmp:<i>:age users:male
    DEL tmp:<i>:activity 
    DEL tmp:<i>:age

I realize that this requires a few calls to redis; but I thinks it is 
preferable to having to transport the sets back and forth to do the 
intersection.

What do you think?

- Jake

Original issue reported on code.google.com by jacob.ba...@gmail.com on 16 Aug 2010 at 10:17

djveremix / redis

[Feature request] Sorted Set and Set intersections #306