[SaifAlHarthi]

Great article!. While reading it I see some similarities with "Plan Stitching" from MSR as shown here https://www.microsoft.com/en-us/research/uploads/prod/2018/0.... It is interesting to see what the performance differences between the two. Also, I am curious of why build a query optimizer from scratch when you can adopt or port something like Orca?

[andydb]

Interesting MSR paper. With regards to Orca, we did take a look at it. It's an OLAP optimizer written in C++ (and very lightly commented and documented, unfortunately), and we wanted a Go-based optimizer that was more integrated with our codebase, as well as targeted at OLTP scenarios (as example Orca supports parallel search, which makes sense in OLAP, but not so much in OLTP). There is quite a bit of overlap, though, and we read their excellent paper and consulted the code from time to time (I hereby invoke a curse on Hungarian notation, which makes reading their code quite painful). We also suspect that Greenplum did not open source some key bits of the optimizer code, such as their search prioritization algorithms.

[SaifAlHarthi]

Yes, that code was painful indeed (was trying to port it at one time). On another note are there any plans on adding advisory tools for database tuning (such as AutoAdmin from MSR) or adding ML to self-tune depending on workload?

[andydb]

Database tuning tools are not on the near-term roadmap, but I think it's a good idea that we'll want to look at eventually. Using ML to self-tune databases is a hot research subject right now, so we'll be following developments on that front.