Thanks a lot guys for your help. I apologize I did not mention it, but I had the index on article_id unfortunately.
Fred: I tried your LEFT JOIN method and indeed, when I EXPLAIN it the second select is of type eq_ref (vs unique_subquery with my method) so it should be faster. Yet, when I try it on a smaller test DB, the difference seems only marginal I am afraid. It still goes through all the comments rows it seems. I just made a simple test directly in mySQL on my instance: "select count(*) from comments" and even that one does not want to return! I tried to restart mysql: same. I did not know this was even possible. I realize it is now more a mySQL issue than a Rails one, but just in case: have you guys ever been confronted to something like that? I will try partitioning as well. Thanks Pierre On Sep 14, 5:13 pm, Jason Stover <[email protected]> wrote: > On Wed, Sep 14, 2011 at 11:03 AM, Philip Hallstrom <[email protected]> wrote: > > > Another option if you're willing to stick with mysql is to use their ???? > > (can't remember the name) feature. > > It lets you create what appears to be a normal table, but it actually > > splits it up into multiple tables based > > on one of the columns -- in your case... the date. So when you remove the > > old entries you're not touching > > the "latest table". At least if I'm remembering things right. > > > -philip > > I think you're talking about partitioning: > > http://dev.mysql.com/doc/refman/5.1/en/partitioning.html > > -J -- 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.
