CF.DEL

Syntax

CF.DEL key item

Time complexity: O(k), where k is the number of sub-filters

ACL categories: @cuckoo

Removes a single occurrence of item from the Cuckoo filter at key.

Unlike Bloom filters, Cuckoo filters support deletion. Only one occurrence is removed per call, so if item was added multiple times, CF.DEL must be called once per insertion to fully remove it.

Deleting an item that was never added, or deleting more times than it was added, can introduce false negatives for that item. Only delete items that are known to have been added.

Return

Integer reply:

• 1 if the item was found and removed.
• 0 if the item was not found.

Error reply: if key does not exist or is not a Cuckoo filter.

Examples

dragonfly> CF.ADD cf Hello
(integer) 1

dragonfly> CF.DEL cf Hello
(integer) 1

dragonfly> CF.EXISTS cf Hello
(integer) 0

dragonfly> CF.DEL cf Hello
(integer) 0

dragonfly> CF.DEL no_such_key Hello
(error) no such key

See also

CF.ADD | CF.COUNT | CF.COMPACT