Re: why ?????????

which means query data dictionary for table defination , but why go to db blocks ?

-ak

• Original Message ----- To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com> 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
>
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-- 
Author: AK
  INET: oramagic_at_hotmail.com

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