Re: immutable functions vs. join for lookups ? - Mailing list pgsql-performance

From Tom Lane
Subject Re: immutable functions vs. join for lookups ?
Date
Msg-id 25151.1113853826@sss.pgh.pa.us
Whole thread Raw
In response to Re: immutable functions vs. join for lookups ?  (Greg Stark <gsstark@mit.edu>)
Responses Re: immutable functions vs. join for lookups ?  (Enrico Weigelt <weigelt@metux.de>)
List pgsql-performance
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

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