KeysCommand
Time complexity: O(n) (with n being the number of keys in the DB, and assuming keys and pattern of limited length)Returns all the keys matching the glob-style pattern asspace separated strings. For example if you have in thedatabase the keys "foo" and "foobar" the command "KEYS foo*"will return "foo foobar".
Note that while the time complexity for this operation is O(n)the constant times are pretty low. For example Redis runningon an entry level laptop can scan a 1 million keys databasein 40 milliseconds. Still it's better to consider this one ofthe slow commands that may ruin the DB performance if not usedwith care.
Glob style patterns examples:
- h?llo will match hello hallo hhllo
- hllo will match hllo heeeello
* haello will match hello and hallo, but not hillo
Use \ to escape special chars if you want to match them verbatim.Bulk reply, specifically a string in the form of space separated list of keys. Note that most client libraries will return an Array of keys and not a single string with space separated keys (that is, split by " " is performed in the client library usually).
* RANDOMKEY to get the name of a randomly selected key in O(1).
