I'm trying to write an adapter for a custom distributed columnar in-memory database. I don't see much for docs beyond a few simple examples:
http://java.dzone.com/articles/sql-over-anything-optiq https://github.com/julianhyde/optiq-csv/blob/master/TUTORIAL.md I'm particularly interested in how to enable selecting fields from deeply nested children. After much googling, I've only seen a few passing mentions of sub-schemas (in TUTORIAL.md and in the old optiq-dev Google Group), but haven't seen examples. I've also seen mentions of _MAP row types. Which one would be appropriate here? For example, here is a very small part of my Schema: Listings (this is the only top level "table") Fields: - listingId - siteId - etc... Child schemas: - Categories Fields: - categoryId - Keywords Fields: - day - keyword This is a very tiny sample of the full hierarchical schema, showing 2 levels, but in reality schemas are arbitrarily deeply nested. Could anyone provide some guidance here? Is this a good case for implementing many sub-schemas and making them accessible via OptiqSchema#getSubSchema, or is it a _MAP row type as seen here<https://github.com/julianhyde/optiq-csv/blob/master/src/main/java/net/hydromatic/optiq/impl/csv/JsonTable.java#L53>? Thanks, Trevor
