Re: 7.4 Wishlist

Bruce Momjian <pgman@candle.pha.pa.us>

From: Bruce Momjian <pgman@candle.pha.pa.us>
To: "Magnus Naeslund(f)" <mag@fbab.net>
Cc: Stephan Szabo <sszabo@megazone23.bigpanda.com>, pgsql-hackers@postgresql.org
Date: 2002-12-03T05:01:06Z
Lists: pgsql-hackers, pgsql-general
Magnus Naeslund(f) wrote:
> >  select id, sum(sum_col)||'/'||count(*) from table_name
> > group by id;
> >
> > or
> >
> >  select table_name.id, sum(sum_col)||'/'||t2.count from table_name,
> > (select id, count(*) as count from table_name group by id) as t2 where
> > table_name.id=t2.id group by table_name.id,t2.count;
> >
> 
> Give it up already, i was MAKING A POINT, not trying to make an
> optimized count(*) thing :)
> There are other examples that you cannot get around, that will be
> evaluated more than once when a local "user variable" would make it not
> need to.

Here's an even slimmer query that makes a var:
	
	test=> select var1.* from (select 1) as var1;
	 ?column? 
	----------
	        1
	(1 row)

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