In the last weeks / months, I have been working on understanding / improving MySQL startup with many tables.  I already wrote a post about my work (Faster MySQL Startup with Many Tables).  In that post, I link to a bug report (Bug #115988 : Too Much Disk Read on Startup, penalizing deployments with many tables).  In that bug report, I write, without much details, that the

In one of my previous posts, I shared InnoDB table compression statistics for a read-only dataset using the default value of innodb_compression_level (6).  In it, I claimed, without giving much detail, that using the maximum value for the compression level (9) would not make a big difference.  In this post, I will share more details about this claim.

TL;DR: tuning innodb_compression_level is not