how-query-engines-work

I highly recommend "How Query Engines Work" by Andy Grove (author of the Apache Datafusion Query Engine + Apache Ballista Distributed scheduler) It's written in Kotlin and is very intelligible + succinct (99 pages): https://leanpub.com/how-query-engines-work https://github.com/andygrove/how-query-engines-work As a self-assessment, I rewrote the entire implementation from a columnar/vector-based engine (it uses Arrow) to row-based, using JDBC types, and it took me only 2 readthroughs of the book to be able to do that. There's also "Database Design and Implementation" by Edward Sciore

I know two DB bibles which explain how a DB engine actually works. It's much more interesting reading than another SQL manual. But it's not awfully practical if you have no particular interest in DB technology. And both are pretty dense. * https://www.amazon.com/Database-Systems-Complete-Book-2nd/dp * https://www.amazon.com/Database-System-Concepts-Abraham-Silb... There's a very cool not-quite-alternativE: https://leanpub.com/how-query-engines-work. It covers a fair chunk of DB technology but not storage. Definitely check out their repository at https://github.com/andygrove/how-query-engines-work/tree/mai... . A companion to DDIA would be https://www.amazon.com/Database-Internals-Deep-Distributed-S... (especially its treatment of LSM trees which is harder to come by).