Why Nebula is using RocksDB?

Why Nebula is using RocksDB? Why not a more memory efficient KV store? How much minimum Ram is required for Nebula? Is it possible to configure Rocksdb memory buffers?

RocksDB is a stable kv store. Nebula is focusing on graph traversing.

minimum memory: 8GB (and 10 partitions)

Sure, you can config Rocksdb buffers in configs /usr/local/nebula/etc/