On 2/27/06, Bruno Wolff III <bruno@wolff.to> wrote:
> The alternatives to distinct on are painful. They are generally both harder
> to read and run slower.
>
'DISTINCT ON' is evil constuction, because (w/o any 'ORDER BY') it
produses unpredictable result, as 'ORDER BY random()' does.
When newbie types 'random()', he understands what he is doing, but
it's not the case for 'DISTINCT ON' and can lead to mistakes.
--
Best regards,
Nikolay