---image: "Math and Computation/Databases/Postgres/assets/chap_1_blocks.png" publish: true description: "A conceptual guide to Postgres core structures: Tuples, Pages, Tables, and Result Sets." --- ![[chap_1_blocks.png]] # Chapter 1: The Building Blocks & The Art of Procrastination Even the laziest elephant needs a place to sit. Before we can start avoiding work with clever indexes or complex query plans, we must understand the physical constraints of our world. Postgres does not store concepts. It stores bytes. And writing bytes to a spinning piece of rust (the hard drive) is exhausting. In this chapter, we explore the physical anatomy of the beast: - Why data is bundled into little boxes called [[Tuple]]s. - Why those boxes are jammed into slightly larger shipping containers called [[Page]]s to make moving them around easier. - How those containers are stacked into a warehouse called a [[Table]]. - How Postgres creates an ephemeral fantasy world called a [[Result Set]] just to show you what you want to see. And, most importantly, we uncover the ultimate manifestation of the elephant's procrastination: [[MVCC|MVCC (Multi-Version Concurrency Control)]]. When you ask Postgres to delete something, it simply crosses it out with a Sharpie, drops the trash on the floor, and promises its Roomba will sweep it up later.