Chapter 72. Database Physical Storage

Table of Contents

72.1. Database File Layout
72.2. TOAST
72.2.1. Out-of-Line, On-Disk TOAST Storage
72.2.2. Out-of-Line, In-Memory TOAST Storage
72.3. Free Space Map
72.4. Visibility Map
72.5. The Initialization Fork
72.6. Database Page Layout
72.6.1. Table Row Layout
72.7. Heap-Only Tuples (HOT)

This chapter provides an overview of the physical storage format used by PostgreSQL databases.