Re: are hints still necessary in 9i?

I think Tom Kyte may be coming from
the direction of controlling the design
and usage of all aspects of the system.

I know several ways to design a system
that will cripple the optimizer's ability to do anything intelligent - even with the
best possible statistics you can give it.

However, for a reasonably designed
system, it is possible to get pretty close to that 'never'.

Another thought, though, is that there
are some 'uncosted' features in some
releases that can only be enabled by
hinting (e.g. unnesting in 8.1). So that's a reason for costing above and beyond
the usual one of 'the optimizer is using the wrong path'.

--
Regards

Jonathan Lewis
http://www.jlcomp.demon.co.uk

  The educated person is not the person
  who can answer the questions, but the
  person who can question the answers -- T. Schick Jr


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"Ryan Gaffuri" <rgaffuri_at_cox.net> wrote in message
news:1efdad5b.0310080503.12cd6fc8_at_posting.google.com...


> Tom Kyte swears that if you properly analyze your table, the CBO is

at


> the point where you never need hints. I find I still need them

> 'occasionally', though not very often.

>

> anyone else have opinions? anyone who beta tested 10g see an

> improvement in the CBO? IT tends to get a little better with each

> release.