Re: Re: performance when inserting into child tables

On 04/21/2004 04:38:30 PM, Jonathan Lewis wrote:

> Two:
> I've never checked this, but when you do the insert/select on
> the child, it is possible that the normal array insert optimization
> (which reduces the volume of undo and redo significantly) cannot
> take place because of the intervening integrity test on each row.
> In this case, it isn't the child insert that is slow, it's the parent
> insert that's quick. (I'll check this some time, and try to remember
> to report back).

Jonathan, just how will you set about checking that assumption? The only difference, as far as I can see would be a different path through the oracle executable. Are you linking with a profiler or running things through the dbx? The only tool that I have that can potentially apply is tracing with the event 10053. Do you expect the SQL execution path different in the optimizer? I'm extremely curious about the method for checking things like that. Despite all my years of experience, I wasn't able to come up with anything that would allow me to analyze path through the oracle executable itself, although God knows that I tried some rather nasty things, some of which have included the "dis" command, but I didn't become any smarter.

-- 
Mladen Gogala
Oracle DBA



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