| From: | Rod Taylor <rbt(at)sitesell(dot)com> |
|---|---|
| To: | Greg Stark <gsstark(at)mit(dot)edu> |
| Cc: | Gurmeet Manku <manku(at)cs(dot)stanford(dot)edu>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: [PERFORM] Bad n_distinct estimation; hacks suggested? |
| Date: | 2005-04-26 23:10:11 |
| Message-ID: | 1114557011.77587.107.camel@home |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers pgsql-performance |
On Tue, 2005-04-26 at 19:03 -0400, Greg Stark wrote:
> This one looks *really* good.
>
> http://www.aladdin.cs.cmu.edu/papers/pdfs/y2001/dist_sampl.pdf
>
> It does require a single full table scan
Ack.. Not by default please.
I have a few large append-only tables (vacuum isn't necessary) which do
need stats rebuilt periodically.
Lets just say that we've been working hard to upgrade to 8.0 primarily
because pg_dump was taking over 18 hours to make a backup.
--
Rod Taylor <rbt(at)sitesell(dot)com>
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Greg Stark | 2005-04-26 23:28:21 | Re: [PERFORM] Bad n_distinct estimation; hacks suggested? |
| Previous Message | Greg Stark | 2005-04-26 23:03:07 | Re: [PERFORM] Bad n_distinct estimation; hacks suggested? |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Greg Stark | 2005-04-26 23:28:21 | Re: [PERFORM] Bad n_distinct estimation; hacks suggested? |
| Previous Message | Greg Stark | 2005-04-26 23:03:07 | Re: [PERFORM] Bad n_distinct estimation; hacks suggested? |