UNLINK key [key …]

Available since 4.0.0.

Time complexity: O(1) for each key removed regardless of its size. Then the command does O(N) work in a different thread in order to reclaim memory, where N is the number of allocations the deleted objects where composed of.

This command is very similar to DEL: it removes the specified keys. Just like DEL a key is ignored if it does not exist. However the command performs the actual memory reclaiming in a different thread, so it is not blocking, while DEL is. This is where the command name comes from: the command just unlinks the keys from the keyspace. The actual removal will happen later asynchronously.

*Return value

Integer reply: The number of keys that were unlinked.

*Examples

redis> SET key1 "Hello"

"OK"

redis> SET key2 "World"

"OK"

redis> UNLINK key1 key2 key3

(integer) 2