This list is a compilation of readings which are valuable to a general understanding of the operation of Cockroach. This list is extensive (but not exhaustive), don't feel you need to read everything here, it's provided as a way to drill down into topics you find interesting, if you so choose. The entries in each section are roughly organized in recommended order of consumption, but this is not a strict ordering in any sense.

General

Architecture docs: https://www.cockroachlabs.com/docs/stable/architecture/overview.html
The hows and whys of a distributed SQL database by Alex: https://www.youtube.com/watch?v=6OFeuNy39Qg
https://github.com/cockroachlabs/slack-convos

There's been various productive conversations that have taken place in the #transactions channel in slack.

What’s Really New With NewSQL: https://db.cs.cmu.edu/papers/2016/pavlo-newsql-sigmodrec2016.pdf

Storage

Kleppmann - Designing Data Intensive Applications: Chapter 3
A Brief History of Log Structured Merge Trees: https://ristret.com/s/gnd4yr/brief_history_log_structured_merge_trees

Transactions

A History of Transaction Histories: https://ristret.com/s/f643zk/history_transaction_histories
ANSI Critique: https://arxiv.org/pdf/cs/0701157.pdf
Yabandeh: https://drive.google.com/file/d/0B9GCVTp_FHJIMjJ2U2t6aGpHLTFUVHFnMTRUbnBwc2pLa1RN/edit

An extremely well-written explanation of optimistic serializable transactions. I think this is one of the best resources for gaining intuition about transactions.

How CockroachDB Does Distributed, Atomic Transactions: https://www.cockroachlabs.com/blog/how-cockroachdb-distributes-atomic-transactions/
Serializable, Lockless, Distributed: Isolation in CockroachDB: https://www.cockroachlabs.com/blog/serializable-lockless-distributed-isolation-cockroachdb/
Understanding Weak Isolation: http://www.bailis.org/blog/understanding-weak-isolation-is-a-serious-problem/
Read-Only Transaction Anomaly: https://www.cs.umb.edu/~poneil/ROAnom.pdf

Explanation of a surprising and unintuitive anomaly that can occur in Snapshot Isolation

What Does Write Skew Look Like: http://justinjaffray.com/what-does-write-skew-look-like/

A (hopefully) simplified explanation of Fekete 2005.

Fekete 2005: https://www.cse.iitb.ac.in/infolab/Data/Courses/CS632/2009/Papers/p492-fekete.pdf
Empirical Evaluation: http://www.cs.cmu.edu/~pavlo/papers/p781-wu.pdf

Mostly relevant to in-memory databases (which CockroachDB is not), but a good overview of the main components of an MVCC system.

Adya Thesis: http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.32.1760&rep=rep1&type=pdf

Very dense, formal treatment of isolation levels. Not really recommended unless you're trying to win an argument.

Linearizability

Strong consistency models: https://aphyr.com/posts/313-strong-consistency-models
Linearizability vs. Serializability: http://www.bailis.org/blog/linearizability-versus-serializability/

While I think this is a good post, keep in mind when reading it that linearizability and serializability are mostly orthogonal concepts and I think conflating them in this way is confusing.

A Mild Generalization of Linearizability: http://justinjaffray.com/a-mild-generalization-of-linearizability/
Living Without Atomic Clocks: https://www.cockroachlabs.com/blog/living-without-atomic-clocks/

Written by Spencer comparing Cockroach's use of synchronized clocks with Spanner's.

Herlihy+Wing: https://cs.brown.edu/~mph/HerlihyW90/p463-herlihy.pdf

The formal genesis of linearizability. I think reading this is confusing because it's actually slightly different and much more formal from how people talk about linearizability in the real world, but I still think it's valuable. It goes off the rails in section 4, though.

Consensus

Why Consensus: http://justinjaffray.com/why-consensus/

I feel quite strongly that people should start here. I don't think the problem that consensus solves is adequately motivated in most discussions, which is what I tried to rectify with this.

Paxos Made Live: http://www.cs.utexas.edu/users/lorenzo/corsi/cs380d/papers/paper2-1.pdf

Describes the process of building a production system on Paxos. Illuminated for me the purpose of consensus in a lot of ways.

Paxos Made Simple: https://lamport.azurewebsites.net/pubs/paxos-simple.pdf
In Search of an Understandable Consensus Algorithm: https://raft.github.io/raft.pdf

Animation: The Secret Lives of Data: http://thesecretlivesofdata.com/raft/

Scaling Raft: https://www.cockroachlabs.com/blog/scaling-raft/
Flexible Paxos: Quorum Intersection Revisited: https://arxiv.org/pdf/1608.06696.pdf

SQL Execution

Volcano: https://paperhub.s3.amazonaws.com/dace52a42c07f7f8348b08dc2b186061.pdf

The introduction of the general execution model that Cockroach uses. Start here if you know nothing about how SQL statements are executed.

The Design and Implementation of Modern Column-Oriented Database Systems: http://db.csail.mit.edu/pubs/abadi-column-stores.pdf

SQL Optimization/Query Planning

Index Selection in CockroachDB: https://www.cockroachlabs.com/blog/index-selection-cockroachdb-2/

Not especially specific to Cockroach - great as an introduction to index selection

SQL Query Planning: https://github.com/cockroachdb/cockroach/blob/master/docs/RFCS/20171213_sql_query_planning.md
Andy K on Optimizer: The Story So Far (April 2018): https://www.youtube.com/watch?v=wAfAVv9SFIc
Andy Pavlo optimizer lectures

Part 1: https://www.youtube.com/watch?v=qbfPpWnAP-4
Part 2: https://www.youtube.com/watch?v=m7GxSvdV4NU

The Cascades Framework for Query Optimization

Not aware of a PDF, this is what our optimizer is based on, though.

Fundamental Techniques for Order Optimization by Simmen et. al

Explains how to manipulate orders, not aware of a publicly available PDF

pkg/sql/opt/doc.go: https://github.com/cockroachdb/cockroach/blob/master/pkg/sql/opt/doc.go
Optimization of Analytic Window Functions: http://vldb.org/pvldb/vol5/p1244_yucao_vldb2012.pdf

Systems

This section is randomly important because people at Cockroach talks about things in terms of the Google system which introduced them

BigTable: https://static.googleusercontent.com/media/research.google.com/en//archive/bigtable-osdi06.pdf
Spanner: https://static.googleusercontent.com/media/research.google.com/en//archive/spanner-osdi2012.pdf
F1: https://static.googleusercontent.com/media/research.google.com/en//pubs/archive/41344.pdf
Colossus/GFS: http://pages.cs.wisc.edu/%7Eremzi/Classes/736/Spring2000/Papers/gfs-sosp2003.pdf
Online, Asynchronous Schema Change in F1: https://static.googleusercontent.com/media/research.google.com/en//pubs/archive/41376.pdf

Lovely discussion of how the schema changes in F1/Spanner (and Cockroach) work

The internals of PostgreSQL: http://www.interdb.jp/pg/index.html

Other

The Promise, and Limitations, of Gossip Protocols: http://www.cs.cornell.edu/projects/Quicksilver/public_pdfs/2007PromiseAndLimitations.pdf

Database Background