go-mysql-server VS grammars-v4

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.

Might be interested in https://github.com/dolthub/go-mysql-server, which also does this

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

One item under "Scope of this project":

Provide a runnable server speaking the MySQL wire protocol, connected to data sources of your choice.

I just wanted to say thanks for https://github.com/dolthub/go-mysql-server

This is incredibly useful for anyone who wants to build their own DB or wrap another datasource so it's queryable via MySQL protocol.

a very cool project they also maintain is a MySQL server framework for arbitrary backends (in Go): https://github.com/dolthub/go-mysql-server

You can define a "virtual" table (schema, how to retrieve rows/columns) and then a MySQL client can connect and execute arbitrary queries on your table (which could just be an API or other source)

Thanks for this write up! I've been really interested in postgres compatibility in the context of a tool I maintain (https://github.com/mergestat/mergestat) that uses SQLite. I've been looking for a way to expose the SQLite capabilities over a more commonly used wire-protocol like postgres (or mysql) so that existing BI and visualization tools can access the data.

This project is an interesting one: https://github.com/dolthub/go-mysql-server that provides a MySQL interface (wire and SQL) to arbitrary "backends" implemented in go.

It's really interesting how compatibility with existing protocols has become an important feature of new databases - there's so much existing tooling that already speaks postgres (or mysql), being able to leverage that is a huge advantage IMO

I found some benchmarks in the ANTLR project: https://github.com/antlr/grammars-v4/blob/master/java/java/B...

  Project          Parsing/Lexing Ratio

Fortunately, ANTLR provides an open-source repository (antlr/grammars-v4) containing grammar definition files for various languages—including Snowflake SQL. Using this, we can simulate how an AST might be constructed from our child1 model’s SQL.

Perhaps this ANTLR v4 sqlite grammar? [1]

--

1: https://github.com/antlr/grammars-v4/tree/master/sql/sqlite

The issue lurks here too—we need to know how to write the grammar file for the parser. Fortunately, it's not hard to find ready-made options on GitHub, so we'll just take it from here.

https://github.com/antlr/grammars-v4/blob/master/hypertalk/H...

TodoMVC or HyperTalk? False dilemma.

Perhaps the one from ANTLR's collection [0] is a good start (there are also others ANTLR VB6 grammars documented elsewhere). It does require knowing ANTLR, but that should be less effort for someone already familiar with language implementation, particularly, the visitor pattern (my favorite reference [1]).

[0] https://github.com/antlr/grammars-v4/tree/master/vb6

[1] https://craftinginterpreters.com/representing-code.html

Where is the SQLite test suite, please? I'd be very interested.

There are already SQL grammars, check https://github.com/antlr/grammars-v4 specifically in here I think https://github.com/antlr/grammars-v4/tree/master/sql I contributed to one of them, and I wrote my own for some personal work. Be warned, it's very involved, very complex and MSSQL is rather ill-defined.

Names bracket identifiers) in SQL are bloody awful. Sometimes square brackets are even compulsory, and why you can usually replace [...] with the SQL standard "..." , not always! Trust me, it gets worse.

I don't find antlr grammars to be brittle, and while they can lose in performance (by how much I don't know, perhaps quite considerably) they are very easy to maintain and I am very fortunate to have antlr to work with.

This grammar "library" was cited as an example of what the format could look like:.

https://github.com/antlr/grammars-v4

There is everything from assembly and C++ to glsl and scripting languages, arithmetic, games, and other weird formats.