Redis Collection Operations

"Redis Collection Operations "

1.SCard Key

Returns key the cardinality of the collection (the number of elements in the collection).

2.sdiffstore destination key [key ...]

This command works similarly to Sdiff, but it saves the result to the destination collection instead of simply returning the result set.

If the destination collection already exists, overwrite it.

destinationcan be key itself.

3.SINTER key [key ...]

Returns all the members of a collection that are the intersection of all given collections.

Non-existent key is considered an empty set.

When there is an empty set in a given collection, the result is also an empty set (according to the Law of collection Operations).

Reference: http://redisdoc.com/

Redis Collection Operations