Support create/drop database

[jiacai2050]

Describe This Problem

In current implementation, there is only one database(called schema in src), we should support database creation to allow one server holding multiple databases.

Proposal

Support those SQL

create database NAME;
drop database NAME;

As for distributed deployment, ceresmeta need to distribute newly-created database to all servers.

Additional Context

For distributed mode, the default database is created when server start up, it should first communicate with ceresmeta to check whether this database is already existing.

apache/incubator-horaedb-meta#136

[jackbit]

Hi, is it done? any documentation for it? how to implement it?

//->#go-sdk

client, err := ceresdb.NewClient(endpoint, ceresdb.Direct)

if err != nil {
  return err
}

resp, err := client.SQLQuery(context.Background(), ceresdb.SQLQueryRequest{
  Tables: []string{},
  SQL:    "create database NAME;",
})

is it correct? i got this error with those script:

err: add request ctx: no database selected, you can use database in client initial options or WriteRequest/SqlQueryRequest

[jiacai2050]

Hi, this feature hasn't got implemented yet.