| From: | "Vladimir Sitnikov" <sitnikov(dot)vladimir(at)gmail(dot)com> |
|---|---|
| To: | "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | "Robert Haas" <robertmhaas(at)gmail(dot)com>, "Gregory Stark" <stark(at)enterprisedb(dot)com>, "Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov>, "jd(at)commandprompt(dot)com" <jd(at)commandprompt(dot)com>, "Josh Berkus" <josh(at)agliodbs(dot)com>, "Greg Smith" <gsmith(at)gregsmith(dot)com>, pgsql-hackers(at)postgresql(dot)org |
| Subject: | Re: benchmarking the query planner |
| Date: | 2008-12-11 21:54:43 |
| Message-ID: | 1d709ecc0812111354m2f5a7ba5gebc9e1d50b9de913@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
>
>
> I think that would likely be redundant with the histogram.
>
I am afraid I do not get you. I mean histograms should be considered when it
comes to increasing number of MCV entries (at least for numeric/timestamp
values). With histogram lower number of entries could be sufficient to get
reasonable accuracy of estimations.I have no idea how to decide between
automatic switch between histograms and MCV. It might sound crazy one could
compute both histograms and MCV and use them both (and pick an average of
two estimations :) )
Regards,
Vladimir Sitnikov
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Simon Riggs | 2008-12-11 22:04:33 | Re: benchmarking the query planner |
| Previous Message | Simon Riggs | 2008-12-11 21:39:20 | Re: Sync Rep: First Thoughts on Code |