Delete all the keys of all the existing databases, not just the currently selected one. This command never fails.
By default, FLUSHALL will synchronously flush all the databases. Starting with Redis 6.2, setting the lazyfree-lazy-user-flush configuration directive to "yes" changes the default flush mode to asynchronous.
It is possible to use one of the following modifiers to dictate the flushing mode explicitly:
ASYNC: flushes the databases asynchronously
SYNC: flushes the databases synchronously
Note: an asynchronous FLUSHALL command only deletes keys that were present at the time the command was invoked. Keys created during an asynchronous flush will be unaffected.
- Redis version >= 4.0.0: Added the `ASYNC` flushing mode modifier.
- Redis version >= 6.2.0: Added the `SYNC` flushing mode modifier and the **lazyfree-lazy-user-flush** configuration directive.