millrawr

It happens frequently because there's often not support in the underlying systems for mergeable latency sketches (e.g. DDSketch, HDR Histogram, or libcircllhist). There thankfully seems to be slowly increasing amounts of support for doing this the correct way.

Persisting executed transactions to a log with their read/write sets, and then determining if they actually commit also starts to sound like http://web.eecs.umich.edu/~michjc/eecs584/Papers/cidr11_hyde... to me

Also see “Building a Bw-Tree Takes More Than Just Buzz Words” https://hyeontaek.com/papers/openbwtree-sigmod2018.pdf

> Second, our evaluation shows that despite our improvements, the Bw-Tree still does not perform as well as other concurrent data structures that use locks.

Building Query Compilers: http://pi3.informatik.uni-mannheim.de/~moer/querycompiler.pd...

Is the closest to what you actually want that I've ever been able to find, but it is unfinished.

> outside expert on database optimizers run a months-long bootcamp, with the goal of teaching our developers how state-of-the-art optimizers work, complete with homework assignments to read seminal papers on the subject

Any chance you could share more about this? This general area of how to build a production grade SQL optimizer seems to be a thing that's more scattered in tiny pieces across a wide number of papers, or held in peoples' heads, than aggregated in a teaching manner. It seemed that the realistic general advice on how to build a SQL optimizer was to poach someone from the SQL Server team. ;)

I've generally just gone referring back to the unfinished Building Query Compilers[1] when pondering this subject. Not that the hundreds of references don't provide sufficient material to read though as well, but it'd be interesting to hear what a bootcamp like this presented as state of the art.

[1]: http://pi3.informatik.uni-mannheim.de/~moer/querycompiler.pd...

CockroachDB is referred to as the clone here. They once gave a talk literally titled "Towards an Open-Source Spanner" (https://www.youtube.com/watch?v=ndKj77VW2eM), so I don't believe that's an unfair characterization.

I actually asked about this on the mailing list some time ago: http://comments.gmane.org/gmane.comp.lib.judy.devel/244

tl;dr: patent was done for defensive reasons.