BF.SCANDUMP

BF.SCANDUMP returns the Bloom filter at key one chunk at a time, so you can store it outside HotKV or copy it to another key or server with BF.LOADCHUNK.

Start with iterator 0. Each reply gives the next iterator and a chunk of binary data. Pass the iterator back to get the next chunk, and keep every (iterator, data) pair. The dump is complete when the reply’s iterator is 0 (with empty data). The first chunk describes the filter; the others hold its bits.

Do not change the filter while you dump it, or the chunks will not match.

Return value

An array of two elements, the same in RESP2 and RESP3:

Element	Value
1	Integer: the iterator for the next call, or 0 when the dump is complete
2	Bulk string: the chunk’s binary data (empty at the end)

Error replies: ERR not found when the key does not exist, Second argument must be numeric for a non-integer iterator, and WRONGTYPE.

Examples

Keep passing back the iterator from the previous reply. The call that returns iterator 0 with empty data ends the dump:

127.0.0.1:6379> BF.ADD visitors alice
(integer) 1
127.0.0.1:6379> BF.SCANDUMP visitors 145
1) (integer) 0
2) ""
127.0.0.1:6379> BF.SCANDUMP nosuchfilter 0
(error) ERR not found

Compatibility

Same command flow as BF.SCANDUMP in RedisBloom. The chunk format is HotKV’s own: load HotKV dumps into HotKV, not into RedisBloom, and the other way around.

See also

BF.LOADCHUNK, BF.INFO