Read more

MySQL: Disable query cache for database profiling

Tobias Kraze
October 04, 2010Software engineer at makandra GmbH

If you want to see how long your database queries actually take, you need to disable MySQL's query cache. This can be done globally by logging into a database console, run

SET GLOBAL query_cache_type=OFF;
Illustration book lover

Growing Rails Applications in Practice

Check out our e-book. Learn to structure large Ruby on Rails codebases with the tools you already know and love.

  • Introduce design conventions for controllers and user-facing models
  • Create a system for growth
  • Build applications to last
Read more

and restart your rails server.

You can also disable the cache on a per query basis by saying


You also probably want to disable Rails internal (per-request) cache. For this, wrap your code with a call to ActiveRecord::Base.uncached. For example, as an around_filter:

def disable_cache
  ActiveRecord::Base.uncached do

Don't forget to re-enable MySQL query caching later with

SET GLOBAL query_cache_type=ON;
Posted by Tobias Kraze to makandra dev (2010-10-04 16:39)