Re: BUG #14932: SELECT DISTINCT val FROM table gets stuck in aninfinite loop

On 2017-11-28 09:55:13 -0500, Todd A. Cook wrote:
> 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.

To make sure we're on the same page, this is data intentionally created
to have a lot of hash collisions, is that right?

Greetings,

Andres Freund