2010/3/29 Marko Tiikkaja <marko.tiikkaja@cs.helsinki.fi>:
> On 2010-03-29 11:19 +0200, Pavel Stehule wrote:
>> postgres=# explain select a from a left join b on true;
you have a true.
I forgot SELECT DISTINCT
regards
Pavel
>
> This is effectively a cross join and it would give wrong answers. Try
> SELECT a FROM a LEFT JOIN b ON a.a = b.b;
>
>
> Regards,
> Marko Tiikkaja
>
