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Re: Query not using indexes

From: Dave <david.sharples3_at_ntlXworld.com>
Date: Thu, 08 Jul 2004 00:39:43 GMT
Message-ID: <jJ0Hc.558$em4.73@newsfe3-gui.ntli.net>

"hastenthunder" <hastenthunder_at_hotmail.com> wrote in message news:3s%Gc.578$Ny6.1570_at_mencken.net.nih.gov...
>
> "Dave" <david.sharples3_at_ntlXworld.com> wrote in message
> news:9g0Hc.495$em4.332_at_newsfe3-gui.ntli.net...
> >
> > "hastenthunder" <hastenthunder_at_hotmail.com> wrote in message
> > news:kj%Gc.577$Ny6.1552_at_mencken.net.nih.gov...
> > >
> > > "Dave" <david.sharples3_at_ntlXworld.com> wrote in message
> > > news:C20Hc.476$em4.117_at_newsfe3-gui.ntli.net...
> > > >
> > > > "hastenthunder" <hastenthunder_at_hotmail.com> wrote in message
> > > > news:vL_Gc.576$Ny6.1485_at_mencken.net.nih.gov...
> > > > > Hi,
> > > > >
> > > > > A query of mine in Oracle 9i R2 chooses to perform a full table
scan
> > of
> > > 1
> > > > > million row instead of using the index.
> > > > > I'm using CBO and just computed the statistics for the table.
> > > > >
> > > > > Can someone help?
> > > > >
> > > > > Thanks
> > > > >
> > > > >
> > > >
> > > > exec
> > dbms_stats.gather_table_stats('SCHEMA_NAME','TABLE_NAME,casacde=true)
> > > >
> > > > are you sure a fts is a bad thing -
> > > >
> > > >
> > >
> > > Done that. Computed fresh statistics before sending the issue out via
> > > analyze table command (its old, I know).
> > > Just did it again using dbms_stats, still does not work...
> > > Strange.., the query certainly access a substantial number of rows....
> > >
> > >
> >
> > if you are getting most of the rows back, fts is good
> >
> > see
> >
>

http://asktom.oracle.com/pls/ask/f?p=4950:8:::::F4950_P8_DISPLAYID:4433887271030
> >
> >
>
> Thanks Dave, you are right.
> However, I'm only getting a single row back (out of 1 million).
>
> SELECT fieldA
> FROM tableA
> WHERE fieldB = 'xxx'
>
> And fieldB is indexed.
> Seems like a very simple query, with fresh statistis.
> That's why this is puzzling me so much....
>
>

try hinting thr query, make sure your index is valid and ok

a well formed valid hint will be taken Received on Wed Jul 07 2004 - 19:39:43 CDT

Original text of this message

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