| From: | "Scott Marlowe" <scott(dot)marlowe(at)gmail(dot)com> |
|---|---|
| To: | "Chris Kratz" <chris(dot)kratz(at)vistashare(dot)com> |
| Cc: | "Joshua D(dot) Drake" <jd(at)commandprompt(dot)com>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Planner mis-estimation using nested loops followup |
| Date: | 2008-03-18 19:46:51 |
| Message-ID: | dcc563d10803181246sbdc7425u838ff2baf70faeb6@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-performance |
On Tue, Mar 18, 2008 at 9:58 AM, Chris Kratz <chris(dot)kratz(at)vistashare(dot)com> wrote:
> Y, turning nested loops off in specific cases has increased performance
> greatly. It didn't fix the planner mis-estimation, just the plan it chose.
> It's certainly not a panacea, but it's something we now try early on when
> trying to speed up a query that matches these characteristics.
I have to admit I've had one or two reporting queries in the past that
turning off nested_loop was the only reasonable fix due to
misestimation. I'd tried changing the stats targets etc and nothing
really worked reliably to prevent the nested_loop from showing up in
the wrong places.
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Gregory Stark | 2008-03-18 19:46:53 | Re: What is the best way to storage music files in Postgresql |
| Previous Message | Gregory Youngblood | 2008-03-18 18:52:16 | Re: What is the best way to storage music files in Postgresql |