Re: [HACKERS] Idea for speeding up uncorrelated subqueries

Bruce Momjian <maillist@candle.pha.pa.us> writes:
> Isn't it something that takes only a few hours to implement.  We can't
> keep telling people to us EXISTS, especially because most SQL people
> think correlated queries are slower that non-correlated ones.  Can we
> just on-the-fly rewrite the query to use exists?

I was just about to suggest exactly that.  The "IN (subselect)"
notation seems to be a lot more intuitive --- at least, people
keep coming up with it --- so why not rewrite it to the EXISTS
form, if we can handle that more efficiently?
        regards, tom lane