Re: WTF with hash index? - Mailing list pgsql-general

From Andreas Kretschmer
Subject Re: WTF with hash index?
Date
Msg-id f3d155d3-ede5-44da-a472-ef47abe20b2a@a-kretschmer.de
Whole thread Raw
In response to Re: WTF with hash index?  (Ron <ronljohnsonjr@gmail.com>)
Responses Re: WTF with hash index?
List pgsql-general

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



pgsql-general by date:

Previous
From: Ron
Date:
Subject: Re: WTF with hash index?
Next
From: Ron
Date:
Subject: Re: WTF with hash index?