Lei, HUANG

> Thanks for the feedback. I'll fix this soon Currently I'm Ok with the catalog/schema name issue and marked these are resolved. Please fix other comments and we can merge...

MySQL protocol now only supports reading and writing data, more functionalities is under active developing. `EXPLAIN` will soon be supported.

> How to support `Explain` syntax for this? can i try it? We'd appreciate any contribution, please reach us if you need any help! As to implementing `EXPLAIN` statement in...

Anyway if MySQL protocol handler receives any statement that is currently not supported, it should return an `UnsupportedError` instead of just panicking. We will fix this.

> > > How to support `Explain` syntax for this? can i try it? > > > > > > We'd appreciate any contribution, please reach us if you need...

Don't think that's an issue, allowing `.` in table name will cause confusion, since full qualified table name already uses `.` as the delimiter between catalog name and schema name....

> @v0y4g3r just to clarify, is this designed to disable mysql server in `datanode`, or to remove mysql protocol support in standalone mode? Both frontend and datanode will start MySQL...

> In standalone mode, why dn needs a mysql server? dn could only expose local grpc service for fe. > > To be clarify: > > - In standalone mode,...

I'm afraid that is related to frontend gRPC proto refactoring what @fengjiachun is working on. Maybe we need two kinds of protos, for insert API, - for protos released to...

We may also need to refactor `Vector` to separate vector's logical type from it's internal representation like discussed in #203