Re: immutable functions vs. join for lookups ?

Greg Stark <gsstark@mit.edu> writes:
> Tom Lane <tgl@sss.pgh.pa.us> writes:
>> It would be interesting sometime to try to teach the planner about
>> inlining SQL-language functions to become joins.  That is, given

> The Inlining of the function is presumably a side-issue. I have tons of
> queries that use subqueries in the select list for which the same behaviour
> would be appropriate.

Yeah, I was actually thinking about a two-step process: inline the
function to produce somethig equivalent to a handwritten scalar
sub-SELECT, and then try to convert sub-SELECTs into joins.

            regards, tom lane