Re: Virtual Private Databases

Setting event 10730 causes the generated in-line view to be dumped every time a new query is parsed. You could also consider adding calls to utl_file in the predicate function to log information about the call.

Be very cautious about generating correlated subqueries in the predicate function - it can add a disastrous overhead to queries. Ideally you should try to restrict the function to generate predicates that examine sys_context() or constants.

--
Jonathan Lewis

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

Author of:
Practical Oracle 8i: Building Efficient Databases
See http://www.jlcomp.demon.co.uk/book_rev.html

Seminars on getting the best out of Oracle
See http://www.jlcomp.demon.co.uk/seminar.html






Connor McDonald wrote in message <9hdaf3$ah$1_at_news.chatlink.com>...


>My only gripe (as a tuner) is that once they're in, its bloody hard to see

>exactly what SQL's are actually being run... I suppose thats where the

>"private" in "virtual private database" comes from :-)

>

>--

>==============================

>Connor McDonald

>

>http://www.oracledba.co.uk

>

>"Some days you're the pigeon, some days you're the statue..."

>"Thomas Kyte" <tkyte_at_us.oracle.com> wrote in message

>news:9hcqeo017i6_at_drn.newsguy.com...

>> In article <Vlk_6.850$Qn3.837057_at_news2.news.adelphia.net>, "James says...

>> >

>> >I am currently developing an internal web app using VPD although I am

 only


>> >using it to separate two specific user types and store their information

 in


>> >a common schema. For me, it has been worth it since I don't have to

 bother


>> >with differing views in my code. VPDs are tricky to conceptualize and

>> >difficult to get working at first. Maintenance has been no problem for

 me


>> >yet. I would like to see this technique simplified in future versions of

 the


>> >DB.

>> >

>>

>> can you expand on that train of thought?

>>

>> What was hard?

>>

>> >"Todd Rubel" <trubel_at_oakgroup.com> wrote in message

>> >news:d272bee7.0106260843.6d40fc92_at_posting.google.com...

>> >> I was wondering how many people have used this feature?  We are

>> >> looking to implement it in the next version of our product and some of

>> >> what I have read has been unfavorable.  Just wondering what some more

>> >> people think.

>> >>

>> >> Are they hard to create?

>> >>

>> >> Are they hard to maintain?

>> >>

>> >> Have any general feelings on the topic?

>> >

>> >

>>

>> --

>> Thomas Kyte (tkyte@us.oracle.com)             http://asktom.oracle.com/

>> Expert one on one Oracle, programming techniques and solutions for

 Oracle.


>> http://www.amazon.com/exec/obidos/ASIN/1861004826/

>> Opinions are mine and do not necessarily reflect those of Oracle Corp

>>

>

>