Returns all keys matching pattern. An error is thrown if over 10,000 keys are in the db to protect
against an out of memory state, although this limit can be changed.
Use \ to escape special characters if you want to match them verbatim.
String array with the list of matching keys, error if there are over 10,000 keys. There is no ordering invariant on the returned keys.
$ ZADD z_key 1.0 v1
$ SADD key val
Get all keys in the db.
$ KEYS *
1) "key" 2) "z_key"
Get keys matching a specific pattern.
$ KEYS ?ey