Re: OCP - Performance Tuning

"Richard Foote" <richard.foote_at_bigpond.com> wrote in message news:sEtZ9.35098$jM5.89854_at_newsfeeds.bigpond.com...
> > 4. The cost-based optimizer can choose between a nested
> > loops join and a sort merge join operation. All tables are
> > analyzed and the OPTIMIZER_MODE is set to FIRST_ROWS.
> > Which execution plan will be the result?
> >
> > a. The sort-merge join.
> > b. The nested loops join.
> > c. This depends on some sort parameter values.
> > d. This depends on the number of rows in each table.
> >
>
> Hi Jonathon,
>
> This sounds like a "8i Performance Tuning" question. There are a few ifs
and
> buts with this but knowing the course material as I do, I would strongly
> suspect b. is the answer they're looking for.

I must admit that that is my suspicion, as telemachus points out it is probably the most common plan as well in practice. I still think that I can only justify C) at all to myself and then that the whole thing is far from satisfactory.

>
> However, really what does it matter. You can get this and 30% or so of the
> other questions wrong and still pass the exam ;)

I think that it matters because the OCP is an industry recognized qualification**. I suspect that all of us who have so far contributed to this thread would say that none of the answers was an acceptable answer in and of itself, that vital information was missing and that other alternative plans don't get a mention. If you have a qualification that employers look to as a yardstick, and employees look to as a validation of their knowledge,experience and ability to do the job having papers stuffed full of inadequate questions rather scuppers the whole enterprise.

• Industry recognised = specified in job ads, funded by employers and individuals as of economic worth and referred to by industry publications/suppliers etc. As distinct from proving X,Y or Z. -- Niall Litchfield Oracle DBA Audit Commission UK