FLUSHDB
Syntax
FLUSHDB
Time complexity: O(N) where N is the number of keys in the selected database
ACL categories: @keyspace, @write, @slow, @dangerous
Delete all the keys of the currently selected DB. This command never fails.
Note: an asynchronous FLUSHDB command only deletes keys that were present at the time the command was invoked. Keys created during an asynchronous flush will be unaffected.