KEYS _pattern_

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 of

the slow commands that may ruin the DB performance if not usedwith care*.

In other words this command is intended only for debugging and *special* operations like creating a script to change the DB schema. Don't use it in your normal code. Use Redis Sets in order to group together a subset of objects.

Glob style patterns examples:

* h?llo will match hello hallo hhllo* h*llo will match hllo heeeello* h[ae]llo will match hello and hallo, but not hillo

Use \ to escape special chars if you want to match them verbatim.

Return value

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).