| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com> |
| Cc: | Alvaro Herrera <alvherre(at)2ndquadrant(dot)com>, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>, Alexander Korotkov <a(dot)korotkov(at)postgrespro(dot)ru>, Mark Dilger <hornschnorter(at)gmail(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: improving GROUP BY estimation |
| Date: | 2016-04-02 14:59:16 |
| Message-ID: | 31529.1459609156@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com> writes:
> Here's an updated patch with references to both papers, and a more
> detailed justification for the formula, along with the other changes
> discussed. Note that although equation (2) in the Dell'Era paper looks
> different from the Yao formula, it's actually the same.
Looks good to me.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Andreas 'ads' Scherbaum | 2016-04-02 14:59:50 | Small typo in a comment in pg_regress.c |
| Previous Message | Tomas Vondra | 2016-04-02 14:31:45 | Re: Using quicksort for every external sort run |