---
title: "DBMS Storage Format"
type: concept
source: https://www.jemoka.com/posts/kbhdbms_storage_layer/
confidence: high
status: active
---

Database Page each Database Page is given a unique identifier; a page ID could be unique per DBMS, per DB, or per table&mdash;page IDs is indirection to physical location.
a Database Page is a fixed-size block of data tuples meta-data indicies log records &hellip; most systems do not mix page types (don&rsquo;t mix different tables, do not mix different types, etc.) some systems require a page to be self contained (no pointers, etc.) &mdash; for fault tolerance Whoops, we accidentally overloaded a word Hardware Page (4kb, i.e. a block on the physical disk) OS Page (usually a block, notionally different for now but abstracted, 2mb, 1gb) Database Page each Database Page is automatically read/written
