pgcow VS dolt

https://github.com/Photonios/pgcow that supports ZFS.

BTRFS is not that scary. Quota and RAID56 is broken but other features have been stable quite some time. Btrfs is used by default for few Linux distros and Facebook makes quite heavy use of it on their servers https://lwn.net/Articles/824855/

I have been running btrfs on all of my machines since 2016 as transparrent file compression helps a lot with keeping disk usage down.

Btrfs RAID1 even saved my data once when one of the SSD's decided to die suddenly.

For maximum performance you should run databases on top of XFS anyway. It also supports per-file COW via relinks.

We built a MySQL-compatible one and are building a Postgres-compatible one :-) Free and open source.

https://github.com/dolthub/dolt

We use the reset functionality to speed up our tests.

https://www.dolthub.com/blog/2022-06-10-enginetest-perf/

Hi, this is my project :)

For us this package is most important as the query engine that powers Dolt:

https://github.com/dolthub/dolt

We aren't the original authors but have contributed the vast majority of its code at this point. Here's the origin story if you're interested:

https://www.dolthub.com/blog/2020-05-04-adopting-go-mysql-se...

It's a pretty good default stance, yeah.

We have been trying to convince people to use our new database [1] for several years and it's an uphill battle, because Postgres really is the best choice for most people. They really have to need our unique feature (version control) to even consider it over Postgres, and I don't blame them.

[1] https://github.com/dolthub/dolt

We implemented a query optimizer with a flexible intermediate representation in pure Go:

https://github.com/dolthub/go-mysql-server

Getting the IR correct so that it's both easy to use and flexible enough to be useful is a really interesting design challenge. Our primary abstraction in the query plan is called a Node, and is way more general than the IR type described in the article from OP. This has probably hurt us: we only recently separated the responsibility to fetch rows into its own part of the runtime, out of the IR -- originally row fetching was coupled to the Node type directly.

This is also the query engine that Dolt uses:

https://github.com/dolthub/dolt

But it has a plug-in architecture, so you can use the engine on any data source that implements a handful of Go interface.

Just want to point out that we're announcing development on the project. It's absolutely not ready for mainstream use yet! We have Dolt (https://github.com/dolthub/dolt) which is production-ready and widely in use, but it uses MySQL's syntax and wire protocol. We are building the Dolt equivalent for PostgreSQL, which is DoltgreSQL, but it's only pre-alpha.

Interesting that branching is now better supported and almost free. I wonder if merging can be simplified or whether it already is as simple and as fast as it can be?

I guess I am inspired by Dolt’s ability to branch and merge: https://github.com/dolthub/dolt