Gan Ziheng

是的，和 `read_only` 是重复的，可以考虑删掉 `create_if_not_exists`。

> I think such read lock is only necessary for fetching associated Tables from LevelHandler and the exact read work can be done outside the lock. Yes, we currently perform...

> > I think if we already get the table, it will not be dropped until nobody use it. > > It takes a little more time when do the...

> Why not define `seek_to_first` and `seek_to_last` just like what rocksdb does? Currently, `rewind` is the same as `seek_to_first`, and `to_last` added int this pull request is actually equivalent with...

> Generally LGTM. But I wonder if there is any use case inside AgateDB that we will need to do both forward iterating and backward iterating on a single iterator?...

> > > Generally LGTM. But I wonder if there is any use case inside AgateDB that we will need to do both forward iterating and backward iterating on a...

> What's the error If we put entries enough to cause compaction in memory mode, we would get this error. I tried to add test for this, but it will...

Column Family 目前并不支持，下一阶段计划增加这一功能。但不是以多个实例的方式，而是考虑把 Column Family 的值当作键的前缀来实现。

确实是个问题。如果使用键前缀的方法，就不好为每个 Column Family 进行单独的配置，以及方便地删除 Column Family。 我去看一下 RocksDB 的实现。我认为增加实例的方式是可行的，但不是一个好的方案。

> A question here. I see we protect the order of Requests send to write channel the same as commit_ts and I wonder why? For WAL in order? That's because...