functions

Stored procedures encapsulate business logic in database. Functions return values; procedures don't (PostgreSQL 11+). I use functions for reusable calculations, data transformations. PL/pgSQL provides procedural language—variables, loops, conditionals

Closures allow functions to access variables from outer scopes even after outer function returns. I create closures when inner functions reference outer function variables. Lexical scope means functions look up variables where they're defined, not whe