We implemented a query optimizer with a flexible intermediate representation in pure Go: https://github.com/dolthub/go-mysql-server https://github.com/dolthub/

We implemented a query optimizer with a flexible intermediate representation in pure Go: https://github.com/dolthub/go-mysql-server 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 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.