Re: [HACKERS] No: implied sort with group by

From: "Thomas G(dot) Lockhart" <lockhart(at)alumni(dot)caltech(dot)edu>
To: Darren King <darrenk(at)insightdist(dot)com>
Cc: pgsql-hackers(at)postgresql(dot)org
Subject: Re: [HACKERS] No: implied sort with group by
Date: 1998-01-29 03:14:37
Message-ID: 34CFF41C.2C5D9B1E@alumni.caltech.edu
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

> > postgres=> select b,c,sum(a) from t1 group by b,c;
> > b|c|sum
> > -+-+---
> > |x| 5
> > |z| 3
> > |x| 0
> > (3 rows)
> >
> > postgres=> select * from t1;
> > a|b|c
> > -+-+-
> > 1| |x
> > 2| |x
> > 2| |x
> > 3| |z
> > 0| |x
> > (5 rows)
> >
> > I just inserted a single out-of-order row at the end of the table which, since the
> > integer value is zero, should have not affected the result. Sorry I didn't understand
> > the nature of the test case.

> Hmmm...is this a grouping problem or an aggregate problem? Or both? The first
> query above should have the data sorted before aggregating, shouldn't it, or I
> am still missing a piece of this puzzle?

fwiw, I see the same incorrect behavior in v6.2.1p5.

- Tom

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Bruce Momjian 1998-01-29 04:58:15 6.3 CHANGES list
Previous Message The Hermit Hacker 1998-01-28 23:58:54 Re: [HACKERS] postmaster crash and .s.pgsql file