| From: | "Todd A(dot) Cook" <tcook(at)blackducksoftware(dot)com> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Thomas Munro <thomas(dot)munro(at)enterprisedb(dot)com> |
| Cc: | Andres Freund <andres(at)anarazel(dot)de>, Tomas Vondra <tomas(dot)vondra(at)2ndquadrant(dot)com>, PostgreSQL Bugs <pgsql-bugs(at)postgresql(dot)org> |
| Subject: | Re: BUG #14932: SELECT DISTINCT val FROM table gets stuck in an infinite loop |
| Date: | 2017-11-28 14:55:13 |
| Message-ID: | 8ee9458d-1556-1cf4-9cea-ff926a9a99d5@blackducksoftware.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-bugs |
On 11/27/17 23:03, Tom Lane wrote:
>
> Note that the sample data has a lot of collisions:
>
> regression=# select hashint8(val), count(*) from reproducer group by 1 order by 2 desc;
> hashint8 | count
> -------------+-------
> 441526644 | 2337
> -1117776826 | 1221
> -1202007016 | 935
> -2068831050 | 620
> 1156644653 | 538
> 553783815 | 510
> 259780770 | 444
> 371047036 | 394
> 915722575 | 359
> ... etc etc ...
In case it matters, the complete data set will have some outlier values with 10k to 100k
collisions in this column.
-- todd
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tomas Vondra | 2017-11-28 15:02:19 | Re: BUG #14932: SELECT DISTINCT val FROM table gets stuck in an infinite loop |
| Previous Message | Todd A. Cook | 2017-11-28 14:49:34 | Re: BUG #14932: SELECT DISTINCT val FROM table gets stuck in an infinite loop |