Storage Internals Heap Storage TOAST, FSM & Visibility Map MVCC

Storage Internals

Storage Internals

How Postgres actually stores rows on disk, and why old ones stick around.

How Postgres actually stores rows on disk, and why old ones stick around.

Sections

4.1
Heap StoragePages, tuples, and relation files on disk
4.2
TOAST, FSM & Visibility MapStoring large values and tracking free space
4.3
MVCCxmin/xmax, snapshots, and visibility rules

JSON & Arrays

JSONB, arrays, and when to reach for them

Heap Storage

Pages, tuples, and relation files on disk