| From: | Nathan Boley <npboley(at)gmail(dot)com> |
|---|---|
| To: | Willy-Bas Loos <willybas(at)gmail(dot)com>, postgres performance list <pgsql-performance(at)postgresql(dot)org> |
| Subject: | Re: change sample size for statistics |
| Date: | 2011-06-10 20:07:19 |
| Message-ID: | BANLkTikkkzpxOuvkgiuMx0ywaHgq1u2jng@mail.gmail.com |
| Views: | Whole Thread | Raw Message | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-general pgsql-performance |
[ Sorry, forgot to cc list ]
>> It is said to be 10%. i would like to raise that, because we are getting bas
>> estimations for n_distinct.
>
> More to the point, the estimator we use is going to be biased for many
> ( probably most ) distributions no matter how large your sample size
> is.
>
> If you need to fix ndistinct, a better approach may be to do it manually.
>
> Best,
> Nathan
>
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Guillaume Lelarge | 2011-06-10 20:09:21 | Re: setting up streaming error. Please help |
| Previous Message | Josh Berkus | 2011-06-10 19:58:19 | Re: change sample size for statistics |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Reuven M. Lerner | 2011-06-11 22:37:59 | Re: Triggering autovacuum |
| Previous Message | Josh Berkus | 2011-06-10 19:58:19 | Re: change sample size for statistics |