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) -- Bruce Momjian | http://candle.pha.pa.us pgman@candle.pha.pa.us | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073