The Redis HSTRLEN command allows us to get the length of a value that’s stored in a hash. It returns the string length of the value associated with the specified field at the hash stored in the specified key.

In Redis, the ZUNIONSTORE command works in the same way that ZUNION works, except that it stores the result in a key that we specify.

In other words, it computes the union of the specified sorted sets, then stores the result in the specified key.

In Redis, the ZUNION command returns the union of the specified sorted sets.

In Redis, the ZREMRANGEBYRANK command enables us to remove all members from a sorted set with a rank between a certain range.

In Redis, the ZREMRANGEBYSCORE command enables us to remove all members from a sorted set with a score between a certain range.

In Redis, the ZREMRANGEBYLEX command enables us to use a lexicographical range to remove members from a sorted set. That is, we can specify that all members between a given lexicographical range are removed.

This relies on all members having the same score (which forces lexicographical ordering).

In Redis, the ZREM command removes one or more members from the specified sorted set.

In Redis, the ZINCRBY command increments the score of a given member in a sorted set.

In Redis, the BZPOPMAX command is the blocking variant of the ZPOPMAX command.

The BZPOPMAX command works similar to ZPOPMAX when any of the sorted sets contain elements. That is, it pops a member with the highest score from the sorted set.