On Thu, Oct 12, 2006 at 09:42:55AM -0700, Jeff Davis wrote: > On Thu, 2006-10-12 at 10:14 -0500, Jim C. Nasby wrote: > > The syntax these hints is something arbitrary. I'm borrowing Oracle's > > idea of embedding hints in comments, but we can use some other method if > > desired. Right now I'm more concerned with getting the general idea > > across. > > > > Is there any advantage to having the hints in the queries? To me that's > asking for trouble with no benefit at all. It would seem to me to be > better to have a system catalog that defined hints as something like: > > "If user A executes a query matching regex R, then coerce (or force) the > planner in this way." > > I'm not suggesting that we do that, but it seems better then embedding > the hints in the queries themselves.
My experience is that on the occasions when I want to beat the planner into submission, it's usually a pretty complex query that's the issue, and that it's unlikely to have more than a handful of them in the application. That makes me think a regex facility would just get in the way, but perhaps others have much more extensive need of hinting. I also suspect that writing that regex could become a real bear. Having said that... I see no reason why it couldn't work... but the real challenge is defining the hints. -- Jim Nasby [EMAIL PROTECTED] EnterpriseDB http://enterprisedb.com 512.569.9461 (cell) ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match