CF.ADDNX

Syntax
CF.ADDNX key item
Available in:
Redis Open Source / Bloom 1.0.0
Time complexity:
O(k + i), where k is the number of sub-filters and i is maxIterations
ACL categories:
@cuckoo, @write, @slow,
Compatibility:
Redis Enterprise and Redis Cloud compatibility

Adds an item to a cuckoo filter if the item does not exist.

This command is similar to the combination of CF.EXISTS and CF.ADD. It does not add an item into the filter if its fingerprint already exists.

Notes:

  • This command is slower than CF.ADD because it first checks whether the item exists.
  • Since CF.EXISTS can result in false positive, CF.ADDNX may not add an item because it is supposedly already exist, which may be wrong.

Required arguments

key

is key name for a cuckoo filter to add items to.

If key does not exist - a new cuckoo filter is created.

item

is an item to add.

Examples 

redis> CF.ADDNX cf item
(integer) 1
redis> CF.ADDNX cf item
(integer) 0

Redis Enterprise and Redis Cloud compatibility

Redis
Enterprise		 Redis
Cloud		 Notes
✅ Supported
 ✅ Flexible & Annual
✅ Free & Fixed

Return information

One of the following:

  • Integer reply: 1 for successfully adding an item to the filter or 0 if the item's fingerprint already exists in the filter.
  • Simple error reply in these cases: invalid arguments, wrong key type, or when the filter is full.