Seonglae ChoRelational Algebra Expression
Not all Graphs are Trees
It's pretty easy to imagine how to represent relational algebra expressions as a tree—they are already structurally rooted trees where each operator has its...
https://buttondown.email/jaffray/archive/not-all-graphs-are-trees
Relational algebra
In database theory, relational algebra is a theory that uses algebraic structures for modeling data, and defining queries on it with a well founded semantics. The theory was introduced by Edgar F. Codd.
https://en.wikipedia.org/wiki/Relational_algebra
Unexplanations: sql is syntactic sugar for relational algebra
This idea is particularly sticky because it was more or less true 50 years ago, and it's a passable mental model to use when learning sql. But it's an inadequate mental model for building new sql frontends, designing new query languages, or writing tools likes ORMs that abstract over sql.
https://www.scattered-thoughts.net/writing/unexplanations-sql-is-syntactic-sugar-for-relational-algebra/