cfis : Rails and Postgresql - Eliminate Hundreds of Thousands of Queries a Day

Comment on Rails and Postgresql - Eliminate Hundreds of Thousands of Queries a Day by rick

Fri, 08 Feb 2008 12:33:17 -0700

Do you have a stack trace for these database calls? The columns, at least, should be cached if cache_classes is true. See: http://dev.rubyonrails.org/browser/trunk/activerecord/lib/active_record/base.rb#L1086

Are you working with dynamic models or anything like that?

Comment on Rails and Postgresql - Eliminate Hundreds of Thousands of Queries a Day by rick

Fri, 08 Feb 2008 12:33:57 -0700

try this instead: http://rubyurl.com/luar

Comment on Rails and Postgresql - Eliminate Hundreds of Thousands of Queries a Day by Charlie

Fri, 08 Feb 2008 13:05:09 -0700

Hi Rick,

Ah interesting - I see what you mean. Did a bit more digging, and it looks like the issues is coming from HasAndBelongsToManyAssociation associations . I updated the bug report with the stack trace. I’m not that familiar with the internal of ActiveRecord, but it looks to me that the column caching code might be better in the base connection adapter class instead of ActiveRecord::Base, which would solve this issue.

Comment on Rails and Postgresql - Eliminate Hundreds of Thousands of Queries a Day by Koz

Fri, 08 Feb 2008 14:04:08 -0700

We also have Base.reset_column_information.

Perhaps it’s worth investigating moving all the caching into the adapters for 2.1, at present the output of Base.inspect will repeatedly query the database too.

Comment on Rails and Postgresql - Eliminate Hundreds of Thousands of Queries a Day by Charlie

Fri, 08 Feb 2008 15:27:51 -0700

Hi Koz,

I just took a quick look, and it doesn’t seem that hard. I’d approach it by renaming the various columns methods on the concrete adapters (Postgresql, mysql, etc) to read_columns. Then I’d add a columns method on AbstractAdapter which checks a cache, and if nothing is found, calls read_methods.

It would also be good to remove the column caching on ActiveRecord::Base but there is on hangup - the looping over column names to set the primary key (which only ActiveRecord::Base knows). Not sure what do about that.

Anyway, hope this helps.