[chrisjc]

For read-oriented interactions...

    ADBC --sql--> Flight SQL Server --flight--> Flight Servers (plural) --> datasources

or

    SELECT * FROM <relation> WHERE ...

where the "relation" is a collection of Arrow stream from a cluster of Flight Servers.

Remember that Flight/Flight-SQL is not a query engine replacement, but rather a way to communicate and exchange data between components with different responsibilities efficiently.