I guess what I'm saying is I'm seeing it far more in production mode than I would expect.
On Aug 1, 11:43 am, Walter Lee Davis <[email protected]> wrote: > On Aug 1, 2011, at 2:39 PM, Michael Kintzer wrote: > > > > > > > I have recently been investigating using PosgreSQL (server version > > 8.3.12), with the 'pg' gem '0.11.0', with our Rails 3.0.7 app. I've > > noticed in the development.log that column information queries are > > made after each request. After inspecting the code for the > > postgresql_adapter and the mysql_adapter I noticed that the > > mysql_adapter executes a similar query but with the :skip_logging > > flag, while the postgresql_adapter goes ahead noisily and logs the > > query: > > > In PostgreSQL, the queries are similar to: > > > SQL (4.4ms) SELECT a.attname, format_type(a.atttypid, a.atttypmod), > > d.adsrc, a.attnotnull > > FROM pg_attribute a LEFT JOIN pg_attrdef d > > ON a.attrelid = d.adrelid AND a.attnum = d.adnum > > WHERE a.attrelid = '"users"'::regclass > > AND a.attnum > 0 AND NOT a.attisdropped > > ORDER BY a.attnum > > > These queries take real time in development mode, so being worried > > about performance I added some extra logging in both adapters to see > > if these queries are also being made in production mode, and to my > > surprise they were made repeatedly for tables with both adapters. I > > was under the impression that ActiveRecord caches table column > > information (at least in production mode) for a given table after the > > first query, and does not need to re-query this information unless the > > client calls the ActiveRecord::Base.reset_column_information method. > > > What's going on here? Am I missing a configuration option that > > enables table column information caching? Or am I just > > misunderstanding the basic concept? > > I think you'll find that (the local equivalent of) these queries > happen all the time in all database servers when you're in development > mode. Production mode enables all the caches, and you won't see them > any more, or certainly not as often! > > Walter > > > > > > > Thanks, > > > Michael > > > -- > > You received this message because you are subscribed to the Google > > Groups "Ruby on Rails: Talk" group. > > To post to this group, send email to rubyonrails- > > [email protected]. > > To unsubscribe from this group, send email to > > [email protected] > > . > > For more options, visit this group > > athttp://groups.google.com/group/rubyonrails-talk?hl=en > > . -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
