mwish

> Based on the current design, typically one Redis key will introduce a maximum of 16384 RocksDB keys (registers). Each value corresponding to a RocksDB key contains only one integer....

> So I think the question is, should we also introduce two mode of hll encoding (sparse and dense layout) and an auto switching policy between these two layout? I...

Other Looks ok to me

> The number of consecutive 0s is calculated from the last 50 digits of the hash value, so the maximum value is 50, and the maximum value stored in a...

@tutububug FYI: 1. bitfield: https://github.com/apache/kvrocks/blob/unstable/src/common/bitfield_util.h#L33 . You can refer to these logic or rewrite the HLL logic using these yourself. A value in HLL using redis' impl would be about...

@PragmaTwice We can first implement that, and optimize writing to HLL step-by-step. Since 2.9 release would be a long time from now.

@jjz921024 Maybe a simpler way is: 1. Config an extra "rocksdb.minor_write_buffer_size" as extra arguments, it can be a bit smaller 2. "default" and "metadata" cf is "major", other column families...

I'm trying to add a code-level refactor on this but I'm feel sick these days, maybe I'll update in coming few days @jjz921024 these style of config here ( https://github.com/apache/kvrocks/issues/2279#issuecomment-2082885791...

@PokIsemaine You can refer to `Service::EvalInternal` for detail

(Thanks! BTW, should 12.1.1 been added also? Or we'd better add it in a separate patch?)