The SQL Join can be thought of as the follows:

• A join is a lookup
• A join is a nested loop over rows
• A join is a nested loop over columns
• A join is compatible alternate realities
• A join is flatMap
• A join is the solution to the N+1 problem
• A join is paths through a graph
• A join is a minimal model
• A join is typechecking
• A join is an operation in the Set monad
• A join is the biggest acceptable relation
• A join is a…join
• A join is a ring product

These are nice ways to illustrate a non-trivial algebraic structure.

TIL the SQLite's built-in VACCUM INTO 'db.bak' and .backup db.bak commands.

SQLite journal modes (DELETE and WAL) really clearly explained. Simple and easily to follow procedures on how SQLite achieve ACID.

SQLite replication through a s3-compatible storage. This seems like a good enough solution to many use cases while being a lot simpler.

A neat trick. TIL sqlite3 :memory:. It starts a sqlite3 cli immediately without needing a file.

The article enumerates many interesting usages. Including JSON input/output/handling, CTE (with expression), and more.