Re: [PATCH] Erase the distinctClause if the result is unique by definition

Hi:

I wrote a patch to erase the distinctClause if the result is unique by 

definition,  I find this because a user switch this code from oracle 

to PG and find the performance is bad due to this,  so I adapt pg for

this as well. 

This patch doesn't work for a well-written SQL,  but some drawback 

of a SQL may be not very obvious,  since the cost of checking is pretty

low as well,  so I think it would be ok to add.. 

Please see the patch for details.   

Thank you.