RE: Difference between count(1) and count(*)
- From: "rob zijlstra" <rmsah@xxxxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>
- Date: Thu, 8 Jul 2004 14:21:16 +0200
Vasan,
Well, your question indicates that you don't have the right attitude to be
an expert. The real question should be: 'How long will it take to ascertain
that in your system count(null) has no meaning and so how long can I write
bills?'
Rob Zijlstra
-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Srinivasan Vasan
Sent: donderdag 8 juli 2004 14:13
To: 'oracle-l@xxxxxxxxxxxxx'
Subject: RE: Difference between count(1) and count(*)
Hi! Tanel,
What exactly would we use a COUNT(NULL) for as it always returns 0?
Cheers,=20
Vasan.
-----Original Message-----
From: Tanel P=F5der [mailto:tanel.poder.003@xxxxxxx]=20
Sent: 08 July 2004 09:38
To: oracle-l@xxxxxxxxxxxxx
Subject: Re: Difference between count(1) and count(*)
I've actually seen an "expert" optimizing the count() statement, by =
using
count(null) "since null means nothing and thus is the fastest" :)
But check this:
SQL> select count(*) from dual;
COUNT(*)
----------
1
SQL> select count(null) from dual;
COUNT(NULL)
-----------
0
Tanel.
----- Original Message -----=20
From: "Jeremiah Wilton" <jwilton@xxxxxxxxxxxxx>
To: <oracle-l@xxxxxxxxxxxxx>
Sent: Thursday, July 08, 2004 9:31 AM
Subject: Re: Difference between count(1) and count(*)
> > On Thu, 8 Jul 2004 11:27:28 +0530 oracle-l@xxxxxxxxxxxxx wrote:
> > > Can you let me know the difference between count(*) and count(1) =
?
> >
> > count(1) is supposed to be more efficient and faster.
>
> Oh boy, here we go.
>
> --
> Jeremiah Wilton
> http://www.speakeasy.net/~jwilton
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