The idea to use SSD/Flash as a cache is not new, and there are different solutions for this, both OpenSource like L2ARC for ZFS and Flashcache from Facebook, and proprietary, like directCache from Fusion-io. They all however have some limitations, that’s why I am considering to have L2 cache on a database level, as an extension to InnoDB buffer pool. Fortunately, there is a project in progress Fla
![L2 cache for MySQL](https://cdn-ak-scissors.b.st-hatena.com/image/square/cc00017c0de607409c1f59e0a1526f68e56aa59d/height=288;version=1;width=512/https%3A%2F%2Fwww.percona.com%2Fblog%2Fwp-content%2Fuploads%2F2012%2F10%2Fl2cache-thrp.png)