Re: Query tuning

Ok guys, thx for your answers, but I know that like '%AAA%' is very expensive, but I don't think that's the problem because the subquery executed alone is near instant:

What about this real examples:

 select ep.no_emiarte, e.titre_o_prg
 from entete_prog ep, entete e, remontage r  where ep.no_emiarte=e.no_emiarte

 and ep.no_emiarte=r.no_emiarte
 and ep.remontage=r.remontage
 and ep.no_emiarte in ('002255-000'); ---------------------> 200 ms

  select ep.no_emiarte, e.titre_o_prg
 from entete_prog ep, entete e, remontage r  where ep.no_emiarte=e.no_emiarte

 and ep.no_emiarte=r.no_emiarte
 and ep.remontage=r.remontage
 and ep.no_emiarte in (select '002255-000' from dual); -----> 13 seconds

In the second case, the 'explain plan' shows that oracle uses index no more
!!!
Received on Wed Oct 23 2002 - 04:27:47 CDT