Re: Using FGAC for implementing history

Jonathan Lewis wrote:
>
> Note inline
>
> --
> Regards
>
> Jonathan Lewis
>
> http://www.jlcomp.demon.co.uk
>
> 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 May 1st
>
> "Vikas Agnihotri" <usenet_at_vikas.mailshell.com> wrote in message
> news:2gk79pF3pv5qU1_at_uni-berlin.de...
> > Jonathan Lewis wrote:
> >
> > > 9i introduced a dramatic change to FGAC to work
> > > around a defect in 8i, but introduced a significant
> > > overhead as a replacement. 10g introduces some
> > > refinements (that I haven't yet examined) that look
> > > as if they are the proper fix for the 8i defect.
> >
> > What 8i defect? What is the dramatic change in 9i? What is the overhead?
> > How does 10g address it? Can you point me to the details? Thanks
> >
>
> If you hold a cursor open (or pl/sql holds it open for you),
> and your security predicate is dependent on context, then
> you can change the context, and find that the change is not
> applied to the cursor.
>
> Part of the work around to this that appeared in 9i is that
> the predicate function is called through an anonymous pl/sql
> block on every execution of the cursor - that's likely to be
> a significant overhead in an OLTP system.
>
> Check the policy defining procedures in 10g - there are
> several different categories of policy, such as
> context dependent
> static
> and so on. I haven't checked, but my guess is that this
> allows some flexibility about how often the predicate function
> executes.

You can 'fiddle' with the 9i using a parameter like "_dynamic_security_predicate" (or something akin to that), but you're still stuck with that 'all or nothing' approach

cheers
Connor

-- 
Connor McDonald
Co-author: "Mastering Oracle PL/SQL - Practical Solutions"
ISBN: 1590592174

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