What Happened to the MySQL Query Cache?

The MySQL Query Cache was once one of the most recognizable performance features in MySQL before being deprecated and eventually removed because it couldn’t scale on modern multicore systems.

Does that mean query caching itself is a bad idea?

This talk revisits why the original MySQL Query Cache failed, why traditional key/value caches became the dominant solution, and how Readyset combines ideas from both approaches to overcome many of their historical limitations.

We’ll understand the anatomy of reads in MySQL and PostgreSQL, discuss cache invalidation strategies, and explore how transparent query caches provide low-latency reads while maintaining correctness.