| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
 |
 | |||
| Oracle FAQ | Your Portal to the Oracle Knowledge Grid | |
|
| |||
Home -> Community -> Mailing Lists -> Oracle-L -> RE: [Q] what difference between count(0), count(1) and count(*)
I ran all three - same results.
I did an explain plan on all three - same result (cost-based optimizer).
I recall some previous discussion on this. The short version is: in the
early versions of Oracle, there was a performance difference, but long ago
Oracle smartened up the CBO to use the same execution plan for all.
Dennis Williams
DBA
Lifetouch, Inc.
dwilliams_at_lifetouch.com
-----Original Message-----
Sent: Wednesday, October 24, 2001 8:30 PM
To: Multiple recipients of list ORACLE-L
Thank you for answer. How about count(0)?
>From: Deepak Thapliyal <deepakthapliyal_at_yahoo.com>
>Reply-To: ORACLE-L_at_fatcity.com
>To: Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
>Subject: Re: [Q] what difference between count(0), count(1) and count(*)
>Date: Wed, 24 Oct 2001 11:41:11 -0800
>
>i think count(*) gives count of all columns .. where
>as count(col1) gives count for col1 ignoring nulls in
>col1
>
>Deepak
>--- aaa aaa <mccdba_at_hotmail.com> wrote:
> > Can anyone tell me what is difference between :
> >
> > select count(*) ... from ..
> >
> > select count(0) ...
> >
> > select coun (1) ...
> > select count(2) ...
> >
> >
> > Thanks.
> >
> >
> >
>_________________________________________________________________
> > Get your FREE download of MSN Explorer at
> > http://explorer.msn.com/intl.asp
> >
> > --
> > Please see the official ORACLE-L FAQ:
> > http://www.orafaq.com
> > --
> > Author: aaa aaa
> > INET: mccdba_at_hotmail.com
> >
> > Fat City Network Services -- (858) 538-5051 FAX:
> > (858) 538-5051
> > San Diego, California -- Public Internet
> > access / Mailing Lists
> >
>--------------------------------------------------------------------
> > To REMOVE yourself from this mailing list, send an
> > E-Mail message
> > to: ListGuru_at_fatcity.com (note EXACT spelling of
> > 'ListGuru') and in
> > the message BODY, include a line containing: UNSUB
> > ORACLE-L
> > (or the name of mailing list you want to be removed
> > from). You may
> > also send the HELP command for other information
> > (like subscribing).
>
>
>__________________________________________________
>Do You Yahoo!?
>Make a great connection at Yahoo! Personals.
>http://personals.yahoo.com
>--
>Please see the official ORACLE-L FAQ: http://www.orafaq.com
>--
>Author: Deepak Thapliyal
> INET: deepakthapliyal_at_yahoo.com
>
>Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
>San Diego, California -- Public Internet access / Mailing Lists
>--------------------------------------------------------------------
>To REMOVE yourself from this mailing list, send an E-Mail message
>to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
>the message BODY, include a line containing: UNSUB ORACLE-L
>(or the name of mailing list you want to be removed from). You may
>also send the HELP command for other information (like subscribing).
-- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: dist cash INET: mccdba_at_hotmail.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: DENNIS WILLIAMS INET: DWILLIAMS_at_LIFETOUCH.COM Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Thu Oct 25 2001 - 11:04:51 CDT
 |
 |