SqlAdvisor column suggestions in GROUP BY — expected behavior?

[Bosiang Huang]

Hi Calcite developers,

I’m experimenting with SqlAdvisor to provide SQL autocompletion hints and
noticed something I’m not sure about.

With a simple in-memory table:

SchemaPlus rootSchema = calciteConnection.getRootSchema();

rootSchema.add("PEOPLE", new PeopleTable());


   - Column suggestions *work* in WHERE clauses:



SELECT * FROM PEOPLE WHERE NA

-- Suggests: NAME


   -  Column suggestions *work* in ORDER BY clauses:



   SELECT * FROM PEOPLE ORDER BY NA

   -- Suggests: NAME


   -  Column suggestions *do NOT appear* in GROUP BY clauses:



   SELECT count(AGE) FROM PEOPLE GROUP BY N

   -- Only suggests SQL keywords, not column names

I’ve tried:

   - Using SqlValidator.Config with withIdentifierExpansion(true)
   - Constructing CalciteCatalogReader with the root schema

but SqlAdvisor still doesn’t suggest columns in GROUP BY positions.

*Questions:*

   1. Is this behavior *by design*, i.e., SqlAdvisor does not provide
   column suggestions in GROUP BY clauses?
   2. If it’s expected, is there a recommended way to get column
   suggestions in GROUP BY?

I can provide a minimal Java example if needed for reference.

Thanks for any guidance!

Best regards,
Bosiang Huang