Re: WTF with hash index?

Am 13.11.2018 um 19:12 schrieb Ron:
> On 11/13/2018 12:07 PM, Andreas Kretschmer wrote:
>>
>>
>> Am 13.11.2018 um 17:42 schrieb Олег Самойлов:
>>> insert into gender (gender) select case when random<0.50 then
>>> 'female' when random<0.99 then 'male' else 'other' end from (select
>>> random() as random, generate_series(1,:table_size)) as subselect;
>>
>> is that really your intended data distibution? 99% male?
>
> select case when random<0.50 then 'female'
> when random<0.99 then 'male'
>             else 'other' end
> from (select random() as random, generate_series(1,:table_size)) as
> subselect;
>
> Shouldn't that make 49% male?

you are right, my fault :-(.
the case - statement will be left if the first condition is true.

Regards, Andreas

--
2ndQuadrant - The PostgreSQL Support Company.
www.2ndQuadrant.com