How a SQL database works

A deep dive into how SQL databases work internally, covering the fundamental data structures that power them. Explains how rows are stored on disk with fixed and variable-length values, how the heap organizes rows into pages for efficient I/O, and why B-trees are used for indexes instead of hash tables. Covers the trade-offs between arrays, hash tables, and relations, and explains why full table scans are slow and how indexes enable logarithmic search performance.