Re: Do DB Links cause high execute and fetch stats?

Niall Litchfield wrote:
> joel garry wrote:
> > I think what this is showing is that all the data has to come over and
> > then be summed. I bet if you summed it on rms2d_to_rms1p it would run
> > 100x faster. Maybe you can CTAS over there and read over the link to
> > the new table?
>
> I agree that this is what is being shown. The r=15 in each line also
> shows that you are only array fetching 15 rows at a time. This could be
> tuned but I'd consider using the DRIVING_SITE hint to get the query
> executed at the remote site - pulling back what looks like nearly 3
> million rows, 15 at a time, probably isn't a great strategy across any
> network. Traces are a great strategy for seeing what actually is
> happening - I'm a little surprised at the requests for more of them
> given your tkprof figures though.
>

DRIVING_SITE is cool, but check metalink for bugs in more complicated queries. I found bug 4618265/4564718 fascinating, wish I could see the base bug.

jg

--
@home.com is bogus.
"Pluto's pain is hawkers' gain"
http://www.signonsandiego.com/uniontrib/20060826/news_1b26pluto.html