sqlite VS clara-rules

SQL (Structured Query Language) databases are relational databases. They organize data into tables with rows and columns, and they use SQL for querying and managing data. Examples include MySQL, PostgreSQL, and SQLite.

SQLite: A lightweight, self-contained SQL database, best for standalone applications, embedded systems, or small-scale applications not requiring a client/server DBMS.

FerretDB is an open source document database that adds MongoDB compatibility to other database backends, such as Postgres and SQLite. By using FerretDB, developers can access familiar MongoDB features and tools using the same syntax and commands for many of their use cases.

Rust stdlib code is quite high quality although not particularly dense due to large amount of comments. Start from the docs, and click any source link: https://doc.rust-lang.org/std/vec/struct.Vec.html

Sqlite is supposedly high quality C code: https://github.com/smparkes/sqlite

For videos of someone (Casey Muratori) writing video game code and debugging it, Handmade Hero: https://handmadehero.org/

A blog post about how to write code by the same author: https://caseymuratori.com/blog_0015

For how to implement a fairly advanced type system, Typing Haskell in Haskell: https://gist.github.com/chrisdone/0075a16b32bfd4f62b7b

But, honestly, you're probably better off writing code yourself and learning by doing.

I've met a few young programmers who heard somewhere that object-oriented programming was bad and they want to get the enlightenment of functional programming that they've heard about. Frequently they travel from job to job like itinerant martial artists always looking for somewhere where they practice the true technique but they always seem disappointed as it is just as easy if not easier to screw up handling errors with monads than it is with exceptions and they find analogies like "a monad is like a burrito" just get them more confused.

As for something profound I'd point you to

https://github.com/cerner/clara-rules

which many people will struggle with because like many other production rules engines in LISP (and many other examples of simple compilers), there is hardly any code! Contrast that to the orders of magnitude larger rules engine Drools

https://github.com/kiegroup/drools

which is so crazy-complicated primarily because the Drools language is Java-based so you need all sorts of things that Clara or CLIPS don't need.