Re: Can outlines be fully reverse engineered?

  • From: "Jonathan Lewis" <jonathan@xxxxxxxxxxxxxxxxxx>
  • To: "Oracle-L Freelists" <oracle-l@xxxxxxxxxxxxx>
  • Date: Fri, 22 Oct 2004 07:36:56 +0100

Not 100% possible - (at least until 10g,
where the new variant on the leading()
hint may help).

If you look at outln.ol$hints, you will see
it has columns
    table_tin
    table_pos

For some queries (particularly ones with
suqueries, which yours may be given the
outline reference to sys_alias_1), Oracle
has a mechanism which effectively dictates
the order of table visit that you cannot emulate
in 8i or 9i.

10g has the leading(t1, t2, t3 ....) hint, though,
which may solve that problem.


Regards

Jonathan Lewis

http://www.jlcomp.demon.co.uk/faq/ind_faq.html
The Co-operative Oracle Users' FAQ

http://www.jlcomp.demon.co.uk/seminar.html
Optimising Oracle Seminar - schedule updated Sept 19th




--
//www.freelists.org/webpage/oracle-l

Other related posts: