How to disable the query cache in rails 2.1
Categories rails, ruby | 1 October, 2008 | By Stephen Sykes
If you need to disable the query cache in rails, it’s not particularly easy to do that.
There is some discussion about it (dated March 2008) here.
Although you can turn all caching off, and you can turn the query cache off explicitly in your code using uncached, there isn’t a way to turn just the query cache off globally at configuration time.
So, then, here’s the monkey patch you need (tested on Rails 2.1.1). Although this is not particularly optimal (in that some query caching related code is still called), it will work. You can put this at the bottom of your environment.rb somewhere, or even better put it in its own file in the initializers directory (e.g. query_cached_off.rb).
module ActiveRecord
module ConnectionAdapters
module QueryCache
private
def cache_sql(sql)
yield
end
end
end
end
RSS
Thanks for sharing!
Very useful monkey patch for developement :)
I recently had to figure out how to disable the query cache, but just for one method, so I used uncached. I wrote up that little article about how to do that in case anybody Googled it (thanks for the link!)
Just curious — why do you need to disable query caching entirely?
I needed to disable query caching to do some testing with my slim-attributes gem ( http://slim-attributes.rubyforge.org/ ).
Conceivably your memory footprint could end up being smaller if you turn off query caching. Probably marginal though.
Um – I’m still very much a rails and ruby newbie, so how do you invoke/use this “monkey patch” An example would be quite helpful. This patch could save me a ton of time, so any help would be greatly appreciated!
Make a file called query_cached_off.rb in the directory config/initializers. Place the code in there. The next time you restart rails the query cache will be turned off.
Stephen,
That’s awesome – thanks so very much, this saves me a ton of time! And thanks for responding so quickly.
Doug