pgBackRest Compression: How Much CPU Is a Smaller Backup Worth?

In this blog post, we’ll compare pgBackRest’s compression algorithms and levels to find where spending more CPU stops buying a meaningfully smaller backup. The short version of the answer, which we’ll build up to with real numbers, is that Zstandard at a low level is the sweet spot, and its default (zst(3)) already sits right on the shoulder of...