which means query data dictionary for table defination , but why go to db blocks ?
-ak ----- Original Message ----- To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Thursday, April 03, 2003 8:13 PM > > There are perfectly valid reasons for querying > a table when no rows are expected to be returned. > > create table x > as > select * > from y > where 1=2; > > ... comes to mind. > > Jared > > On Thursday 03 April 2003 15:58, AK wrote: > > If I execute a query like , > > select count(*) from some_table where 1=2 . > > why does oracle bothers to look at tables . Since there is only one > > condition which is false . > > > > If I write a sql like > > > > select count(*) > > from some_table > > where column_a= :a > > and a is not null; > > > > it should not even go to look at table , but explain plan suggests that it > > does a index /table scan . > > > > -ak > > ---------------------------------------- > Content-Type: text/html; charset="iso-8859-1"; name="Attachment: 1" > Content-Transfer-Encoding: quoted-printable > Content-Description: > ---------------------------------------- > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.net > -- > Author: Jared Still > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (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.net -- Author: AK INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (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).
