Some issues about using calcite

[李天安]

Hi,
        My Name is Tianan Li, recently I’m using your project calcite v1.18.0. 
I have met some issues and I need your help.
        When I connect to postgresql via calcite, I found that I can not get 
remarks of table and columns via DatabaseMetaData.getTables ans 
databaseMetaData.getColumns methods. What’s more, I can not  get primary keys 
of a table via DatabaseMetaData.getPrimaryKeys method.
        Is that something wrong with my usage or a bug?
        Thanks, I’m looking forward your reply.

Best,
Tianan Li