| From: | "Nathan Boley" <npboley(at)gmail(dot)com> |
|---|---|
| To: | "Vladimir Sitnikov" <sitnikov(dot)vladimir(at)gmail(dot)com> |
| Cc: | "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us>, "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 21:33:05 |
| Message-ID: | 6fa3b6e20812111333w4b57b171yb56b853c5be0e5f3@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
> One more direction could be implementing "MCV" for range of values (group
> values and interpolate in between). Consider statistics on timestamp column
> that says that for "2008-December" there are as many X rows, for
> "2008-November" as many as Y, etc. That could be used for rather accurate
> cardinality estimation of "between" cases, while keeping number of entries
> in "MCV" list small.
>
I suggested this earlier (
http://archives.postgresql.org/pgsql-hackers/2008-06/msg00353.php ).
If there's interest, I'd be happy to clean up my patch and submit it
for 8.5
-Nathan
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Gregory Stark | 2008-12-11 21:35:12 | Re: posix_fadvise v22 |
| Previous Message | Tom Lane | 2008-12-11 21:28:28 | Re: benchmarking the query planner |