Re: referencing objects

"Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote in message news:954591001.24433.0.nnrp-08.9e984b29_at_news.demon.co.uk...
>
> I don't think I have missed the point, I have only
> asked you to demonstrate that the point you
> claimed is both true and significant.
>
> a) I presented an argument based on quantity of
> recursive SQL which suggests the 1:2:4 ratio
> you claimed is incorrect.
>
> b) I quoted an example of parsing 4,000 statements
> in 14 seconds which appeared to do considerably
> better than the 1:2:4 ratio that you claimed, and
> incidentally suggests that Oracle is doing better
> at keeping information about public synonyms than
> you imply - hence your point may be true but largely
> irrelevant.
>
>
> Your comment in another post about the 'dependency tables'
> is not only relevant to public synonyms - queries involving
> (particularly) OR-expansion of large IN-lists have always had
> to face the extra burden of potentially large dependency tables,
> a problem addressed by setting an event in later versions of 7.3.
> and removed by the IN-list Iterator operation in the 8.1 optimiser.
>
>
> Of course, my example was running on 8.1 - so it
> is possible that the problem you describe is relevant
> only to an earlier version of Oracle. Either way, I'd be
> interested to see details of an experiment that proves
> your point.
>

My data was for Oracle 8.0.5 and earlier. Maybe that explains it.

No experiment... just the accumulated results of numerous actual consultancy at numerous sites in Australia. One in particular springs to mind, since this was precisely the cause of their problems: a very large telco, system running like treacle, and the simple expedient of elimination of synonyms resulted in dramatic improvements in performance. Seen it numerous times.

Regards
HJR
>
> --
>
> Jonathan Lewis
> Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk
>
> Howard J. Rogers wrote in message <38e5d34b_at_news.iprimus.com.au>...
> >
> >"Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote in message
> >news:954575805.19620.0.nnrp-11.9e984b29_at_news.demon.co.uk...
> >
> >You seem to have missed the point that the structures required to make
> >public synonyms work cannot be 'kept' in the library cache, and that
 there
> >is therefore a tendency for public-synonym-dependent applications to be
> >doing lots more re-parsing than would be 'desirable'. That is precisely
 the
> >point, of course.
> >
>
>
>
>
>
Received on Sat Apr 01 2000 - 00:00:00 CST