Frederick Cheung wrote: > On 20 Dec 2008, at 07:11, Marnen Laibow-Koser wrote: > >> [...] >> >> Very simple: you can profit by indexing on almost anything you're > All of the above is good. To explain a little more if you do > > SELECT * from contacts where contacts.user_id = 2356 > > and there is no index then the database must examine every single row > in the contacts table to see if it has the right user_id whereas if it > has an index it can go straight there. (similar to how if you have a > > Fred
Thanks Marnen and Fred, Does the same logic completely cover joins, or is there something special to consider for those? thanks, jp -- Posted via http://www.ruby-forum.com/. --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
