# How Databases Checkpoint to Disk Without Stopping the World

DevFeed: [How Databases Checkpoint to Disk Without Stopping the World](<https://devfeed.tech/articles/how-databases-checkpoint-to-disk-without-stopping-the-world-39653.md>)

Original publisher: [Read original article](<https://www.gauravsarma.com/posts/2026-03-15_checkpointing-without-stopping-the-world>)

Published: 2026-03-15T00:00:00Z

Content type: tutorial

Language: en

Sources: [Gaurav Sarma's Blog](<https://devfeed.tech/sources/gaurav-sarma-s-blog.md>)

Topics: [Databases](<https://devfeed.tech/topics/databases.md>), [PostgreSQL](<https://devfeed.tech/topics/postgresql.md>)

Tags: [checkpoint](<https://devfeed.tech/tags/checkpoint.md>), [crash-recovery](<https://devfeed.tech/tags/crash-recovery.md>), [databases](<https://devfeed.tech/tags/databases.md>), [latency](<https://devfeed.tech/tags/latency.md>), [postgresql](<https://devfeed.tech/tags/postgresql.md>), [snapshot](<https://devfeed.tech/tags/snapshot.md>), [wal](<https://devfeed.tech/tags/wal.md>)

## AI overview

A tutorial on database checkpointing explains why pausing writes to flush all dirty pages causes latency spikes and throughput stalls. It introduces fuzzy or online checkpointing, including PostgreSQL's WAL-based approach, which allows writes to continue while dirty pages are flushed and uses WAL replay during crash recovery.

## Source excerpt

Your database has gigabytes of dirty pages in memory. At some point they need to hit disk...