Someone I know used to make jokes about their plans to run MySQL 4.0 forever. It wasn't a horrible idea as 4.0 was very efficient and the Google patch added monitoring and crash-proof replication slaves. I spent time this week comparing MySQL 5.7.2 with 5.6.12 and 5.1.63. To finish the results I now have numbers for 4.1.22. I wanted to include 4.0 but I don't think it works good when compiled with
![MySQL 4.1 forever](https://cdn-ak-scissors.b.st-hatena.com/image/square/05581ef874a2b958a6bfb97b59d97b5a0de1ef03/height=288;version=1;width=512/http%3A%2F%2F3.bp.blogspot.com%2F-xBST2OgFFC4%2FUkThpNESX2I%2FAAAAAAAAAr0%2FwSzljc_2-F4%2Fw1200-h630-p-k-no-nu%2Fchart_1%2B%281%29.png)