On Tue, Mar 22, 2005 at 10:41:19AM +0100, Steffen Goeldner wrote:
> Attached is a small benchmark script. The test platform is:
>
> The output looks like:
> 47638 rows
> Finally, let's use the new subroutine approach:
>
> my $rows = sub {
> return if $rs->{EOF};
> my $row = [ map { $rs->Fields( $_ )->{Value} } 0..4 ];
> $rs->MoveNext;
> return $row;
> };
>
> 24 wallclock secs (19.83 usr + 0.50 sys = 20.33 CPU)
>
> Not only that the last approach lead to a much more moderate
> memory utilization, but it also outperforms the other variants
> significantly!
Two sides of the same coin: Memory allocation is slow.
What you're seeing is the same reason that fetchall_* (and selectall_*)
is often slower than fetchrow_*.
http://search.cpan.org/src/TIMB/DBI_AdvancedTalk_2004/sld017.htm
Tim.
