Re: performance of implicit join vs. explicit conditions on inet queries?

"Qingqing Zhou" <zhouqq(at)cs(dot)toronto(dot)edu> writes:
> "Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote
>> No, that's completely irrelevant to his problem. The reason we can't do
>> this is that the transformation from "x << const" to a range check on x
>> is a plan-time transformation; there's no mechanism in place to do it
>> at runtime.

> Not quite understand, sorry ...

> (1) For this query (in an as-is PG syntax, which find out all rectangles lie
> in a given rectangle) :

> SELECT r FROM all_rectangles
> WHERE r << rectangle('(1,9),(9,1)');

No, you're thinking of the wrong << operator. The question was about
the inet network inclusion operator. We have a special case in
indxpath.c to transform "inetcol << inetconstant" into a range check
on the inet variable, much like we can transform a left-anchored LIKE
pattern into a range check on the text variable.

regards, tom lane