# Postgres 19 Compression: from pglz to LZ4

DevFeed: [Postgres 19 Compression: from pglz to LZ4](<https://devfeed.tech/articles/postgres-19-compression-from-pglz-to-lz4-14481.md>)

Original publisher: [Read original article](<https://www.crunchydata.com/blog/postgres-19-compression-from-pglz-to-lz4>)

Author: Christopher Winslett

Published: 2026-07-16T12:00:00Z

Content type: article

Language: en

Sources: [CrunchyData Blog](<https://devfeed.tech/sources/crunchydata-blog.md>)

Topics: [Compression](<https://devfeed.tech/topics/compression.md>), [Databases](<https://devfeed.tech/topics/databases.md>), [Open Source](<https://devfeed.tech/topics/open-source.md>)

Tags: [algorithm](<https://devfeed.tech/tags/algorithm.md>), [automatic](<https://devfeed.tech/tags/automatic.md>), [compression](<https://devfeed.tech/tags/compression.md>), [open-source](<https://devfeed.tech/tags/open-source.md>), [postgres](<https://devfeed.tech/tags/postgres.md>), [postgres-19](<https://devfeed.tech/tags/postgres-19.md>), [production-postgres](<https://devfeed.tech/tags/production-postgres.md>), [speed](<https://devfeed.tech/tags/speed.md>), [storage](<https://devfeed.tech/tags/storage.md>)

## AI overview

This article explains how PostgreSQL compresses table, TOAST, and index data, and examines the planned Postgres 19 change from pglz to LZ4 as the default TOAST compression algorithm.

## Source excerpt

With Postgres 19 switching the default from pglz to LZ4, this post walks through the compression decision path, storage strategies, and index-size limits that shape real-world behavior.