Question around fixed hierarchy for schema

[GavinRay97]

I noticed that the ADBC metadata information assumes a fixed hierarchy:

arrow-adbc/java/core/src/main/java/org/apache/arrow/adbc/core/AdbcConnection.java

Line 58 in 2485d7c

* Get a hierarchical view of all catalogs, database schemas, tables, and columns.

What would the advice be for datasources that don't fit this, like Snowflake/Trino/Dremio where the hierarchy might be:

• datasource.database.schema.table
• postgres1.mydb.public.emps

[lidavidm]

Hmm, real-world edge cases are always fun, thanks for poking around. (Admittedly we should've looked more closely at these.)

We were debating whether to keep the hierarchy or split it into multiple views (akin to Flight SQL), so this might be an argument for splitting them.

Do you have a reference for the Snowflake/Trino behavior? I see examples like the following that document three levels of hierarchy, but not the fourth level:

https://trino.io/docs/current/connector/postgresql.html#querying-postgresql
https://docs.snowflake.com/en/user-guide/databases.html

[lidavidm]

A few people are plotting out an ADBC 1.1.0 API specification already. In #320 I put up a quick solution to this, based on what we talked about before (letting db_schema have a delimiter).