| From: | Josh Berkus <josh(at)agliodbs(dot)com> |
|---|---|
| To: | Greg Stark <gsstark(at)mit(dot)edu> |
| Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, David Fetter <david(at)fetter(dot)org>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: More thoughts about planner's cost estimates |
| Date: | 2006-06-02 22:15:43 |
| Message-ID: | 200606021515.44174.josh@agliodbs.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Greg, Tom,
> But for most users analyze doesn't really have to run as often as
> vacuum. One sequential scan per night doesn't seem like that big a deal
> to me.
Clearly you don't have any 0.5 TB databases.
> > I'd still be worried about the CPU pain though. ANALYZE can afford to
> > expend a pretty fair number of cycles per sampled tuple, but with a
> > whole-table sample that's going to add up.
Agreed. Despite conventional wisdom, most PostgreSQL databases ... even
those with high level OLTP or very large DW ... are CPU-bound. We
really don't want an ANALYZE which is an order-of-magnitude increase in
CPU activity.
--
--Josh
Josh Berkus
PostgreSQL @ Sun
San Francisco
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Todd A. Cook | 2006-06-02 22:24:33 | Re: More thoughts about planner's cost estimates |
| Previous Message | Greg Stark | 2006-06-02 21:46:41 | Re: COPY (query) TO file |