Re: order of nested loop

Tom Lane wrote:
> Joseph Shraibman <jks@selectacast.net> writes:
>
>>How do I read that?  Is it creating a hash out of the data in d, then
>>going through u doing a join?
>
>
> Yeah.  Given the numbers of rows involved, the plan seems pretty
> reasonable --- I doubt you can do a lot better within the context
> you're showing here.  To make it faster you'll have to find a way
> to not need to look at all the rows.
>
>             regards, tom lane
Well there is no reason for it to look at all the rows in d, since it has a filter on u
that should produce much less rows than there on in d.  In both the plan and the actual
the rows returned from u are less than the rows from d