Found in 5 comments on Hacker News
lbruck · 2017-10-10 · Original thread
I like "Architecture of a Database System" by Stonebraker, Hamilton, and Hellerstein (http://db.cs.berkeley.edu/papers/fntdb07-architecture.pdf) for an overview and then "Transaction Processing: Concepts and Techniques" by Gray and Reuter (https://www.amazon.com/Transaction-Processing-Concepts-Techn...) for the storage-side of things. Granted these are a little old (especially G&R) so extra thought must be given for modern hardware (memory, CPU performance, processor counts, network, disks, etc) as well as distributed processing, replication, and consensus.
rusanu · 2016-05-23 · Original thread
Transaction Processing: Concepts and Techniques [0] by Jim Gray and Andreas Reuter. Not so much relational algebra, but everything you need to know to implement a classic relational engine.

[0] https://www.amazon.com/Transaction-Processing-Concepts-Techn...

cafard · 2015-08-14 · Original thread
For implementation of database systems, Gray and Reuter's Transaction Processing: Concepts and Techniques http://www.amazon.com/Transaction-Processing-Concepts-Techni.... For the ideas behind relational databases, I like C.J. Date's Introduction to Database Systems, http://www.amazon.com/Introduction-Database-Systems-C-Date/d....
fogus · 2012-05-18 · Original thread
Dr. Gray wrote "Transaction Processing"[1] that has proven indispensable in my career and a generally great book. I didn't know the man, but he influenced me deeply from afar. RIP.

[1]: http://www.amazon.com/Transaction-Processing-Concepts-Techni...

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