On Apr 18, 9:49 am, jey bal <li...@ruby-forum.com> wrote: > I have following query for find out the total no of counts. > > *************************************************************************** > ************ > > SELECT count(*) > FROM contacts_lists > JOIN plain_contacts ON contacts_lists.contact_id = > plain_contacts.contact_id > JOIN contacts ON contacts.id = plain_contacts.contact_id > WHERE plain_contacts.has_email AND NOT contacts.email_bad AND NOT > contacts.email_unsub AND contacts_lists.list_id = 45897 > > *************************************************************************** > ************ > > It takes 150ms to complete its task. > Is there any another way to run the above query? > Is there any way to reduce the time? is it possible? please tell > me..................................... >
well the first step is to run explain against the query and see what it says. Make sure you've added indexes when appropriate (at a minimum this should include the columns being joined on. You should also index columns used in the where clause that are sufficiently selective (I'd guess that contacts_lists.list_id would be a good candidate). use explain before and after to see the difference adding indexes makes to the query plan Fred > -- > Posted viahttp://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 rubyonrails-talk@googlegroups.com. To unsubscribe from this group, send email to rubyonrails-talk+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/rubyonrails-talk?hl=en.
