I am trying to understand PostgreSQL's FDW and an ODBC driver.
From my understanding, the FDW just makes other data sources look like Postgres tables, essentially a bridge between PostgreSQL and the external data source. So, you would write your own FDW to create the foreign tables and point the foreign table to the external data source(database).
Thus, if you had a NoSQL DB that didn't have a table schema than you would have to use the FDW to flatten the data to a tabular format?
How is this different than what an ODBC driver is doing?