fdbcli flags currently contain a mixture of _ and - (probably for historic reasons). I would propose to unify the flags and only use either _ or - personally I tend to hyphens like recommended in the POSXI standard (https://www.gnu.org/software/libc/manual/html_node/Argument-Syntax.html). Current fdbcli help output:

FoundationDB CLI 6.2 (v6.2.29)
usage: /usr/bin/fdb/6.2/fdbcli

Currently we don't have any mechanism to limit the maximum number of clients that could be handled simultaneously.

This feature should be designed properly. Here is some clue: https://redis.io/topics/clients#maximum-number-of-clients

Right now, to get an acceptable experience in dtlv, one has to use rlwrap, i.e. launch it like this rlwrap dtlv. It would be nice to integrate with jline3 library to have a better experience natively.

Right now, PebblesDB uses a lot of memory for the TableCache (caching metadata) and for the bloom filters used for each sstable.

We want to add a command line option for PebblesDB which would limit the total amount of memory used by PebblesDB for the TableCache and bloom filters.

When using the specified amount of memory, preference should be given first to the table cache, and then bloom

There are no external core dependencies other than LZ4 and Snappy which are not used unless compression is configured. So they should be installable.

libraryDependencies += "io.swaydb" %% "lz4" % "version"
//OR 
libraryDependencies += "io.swaydb" %% "snappy" % "version"

For now we have to exclude

Currently pessimistic_lock will always issue a request.
If heartbeat is enabled, we don't have to lock the same key for multiple times.
For get_for_update-like operations, we can have a separate cache to cache its value.

It would be better and easier to debug a program if the BytesEncoding and BytesDecoding traits could return any error type.

To do so we need to modify the Error enum and more specifically the Encoding and Decoding variants to wrap a Box<dyn Error>.