Returns all keys matching
While the time complexity for this operation is O(N), the constant times are fairly low. For example, Redis running on an entry level laptop can scan a 1 million key database in 40 milliseconds.
KEYS as a command that should only be used in production
environments with extreme care.
It may ruin performance when it is executed against large databases.
This command is intended for debugging and special operations, such as changing
your keyspace layout.
KEYS in your regular application code.
If you're looking for a way to find keys in a subset of your keyspace, consider
Supported glob-style patterns:
\ to escape special characters if you want to match them verbatim.
@multi-bulk-reply: list of keys matching
MSET one 1 two 2 three 3 four 4 KEYS *o* KEYS t?? KEYS *