Re: 7.4 Wishlist
От | Bruce Momjian |
---|---|
Тема | Re: 7.4 Wishlist |
Дата | |
Msg-id | 200212030501.gB3516i17728@candle.pha.pa.us обсуждение исходный текст |
Ответ на | Re: 7.4 Wishlist ("Magnus Naeslund(f)" <mag@fbab.net>) |
Список | pgsql-hackers |
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(1row) -- 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, Pennsylvania19073
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