Examining Flight SQL (redux)

Way back in Chapter 8, Exploring Apache Arrow Flight RPC, we briefly touched on the topic of Arrow Flight SQL and why it was important. Very briefly. Flight SQL is still very new, and while the protocol has stabilized (for the most part), it's very much under development and there are only C++ and Java reference implementations so far. So, first, let's quickly cover the motivations for Flight SQL's development and what it is and isn't.

Why Flight SQL?

We first mentioned the Java Database Connectivity (JDBC) and Open Database Connectivity (ODBC) standards in Chapter 3, Data Science with Apache Arrow. While they have done well for decades, the standards simply don't handle columnar databases well at all. Both of these standards define APIs that are row-based. If the connected database uses a columnar representation of the data, using ODBC/JDBC will require transposing the data not once, but twice! Once for the database to provide...