Re: Index not used

  • From: "Ranko Mosic" <ranko.mosic@xxxxxxxxx>
  • To: "Wolfgang Breitling" <breitliw@xxxxxxxxxxxxx>
  • Date: Thu, 18 May 2006 14:05:50 -0400

Even the following query does FTS:
SELECT *
 2   FROM tab1 t1 ,
 3        tab2 t2
where t1.id = t2.id


rm


On 5/17/06, Wolfgang Breitling <breitliw@xxxxxxxxxxxxx> wrote:

There is no predicate for tab2, the smallest of the three tables, apart from the join predicate. Are there usable indexes on tab1.type and tab3.start_date? Any changes if you add the transitive closure predicate (the optimizer does not do this (yet)): t1.id = t2.id and t2.id = t3.id => t1.id = t3.id It opens additional access paths.

Quoting Ranko Mosic <ranko.mosic@xxxxxxxxx>:

> Hi List,
>
> SELECT *
>  2   FROM tab1 t1 ,
>  3        tab2 t2 ,
>  4        tab3 t3
>  5  WHERE t1.id = t2.id
>  6    AND t2.id = t3.id
>  7    AND t1.type IN
>  8           ('A','B','C')
>  9    AND t3.type = 'A'
> 10* AND t3.start_date = '01-APR-2004'
>
> All join cols are indexed on leading cols. There is FTS on t2 . Stats
are
> fresh and computed .
> Why FTS on t2 ? ( v 9.2 ).
> --
> Regards,
> Ranko Mosic
> Contract Senior Oracle DBA
> B. Eng, Oracle 10g, 9i Certified Database Professional
> Phone: 416-450-2785
> email: mosicr@xxxxxxxxxx
>

http://ca.geocities.com/mosicr@xxxxxxxxxx/ContractSeniorOracleDBARankoMosicMain.html
>


-- regards

Wolfgang Breitling
Oracle 7,8,8i,9i OCP DBA
Centrex Consulting Corporation
www.centrexcc.com




--
Regards,
Ranko Mosic
Contract Senior Oracle DBA
B. Eng, Oracle 10g, 9i Certified Database Professional
Phone: 416-450-2785
email: mosicr@xxxxxxxxxx
http://ca.geocities.com/mosicr@xxxxxxxxxx/ContractSeniorOracleDBARankoMosicMain.html

Other related posts: