FLUSHDB

FLUSHDB [ASYNC | SYNC]

Available since:

Redis Open Source 1.0.0

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.

By default, FLUSHDB will synchronously flush all keys from the database. 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 database asynchronously
• SYNC: flushes the database synchronously

Notes

• 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.
• This command does not delete functions.
• When using Redis Cluster, this command is identical to FLUSHALL since a Redis Cluster supports only one database with an ID of zero.

Behavior change history

• >= 6.2.0: Default flush behavior now configurable by the lazyfree-lazy-user-flush configuration directive.

Return information

History

• Starting with Redis version 4.0.0: Added the ASYNC flushing mode modifier.
• Starting with Redis version 6.2.0: Added the SYNC flushing mode modifier.