Jonathan Lewis wrote:
>
> I have an
> idea, in fact, that when you do single row fetch
> (as opposed to array fetch) in recent versions
> of Oracle, there is actually a hidden optimisation
> that attempts to fetch two rows and buffers the
> second row locally - but this is just a hypothesis
> that I have not yet examined in detail.
>
> Jonathan Lewis
> http://www.jlcomp.demon.co.uk
>
I believe that hypothesis to be pretty true. The Oracle calls now have a
'prefetch size' attribute, which is, I think, turned on by default, to
avoid round-trips. This is a nice feature for all those people who have
been told for the past 15 years to use array fetch and yet don't. Less
nice for those who do, since Oracle does a hidden array fetch of its own
in your back, then you do a local array fetch from its buffers (I have
no idea about the consequences of a mismatch of both array sizes). I
think that you end up copying more bytes when you do things as you ought
to.
--
Regards,
Stephane Faroult
Oriole Software
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Received on Tue May 07 2002 - 15:38:35 CDT
