[Dbix-class] Rapid Data Extraction

[Zbigniew Lukasiak]

Just shooting blindly, but if you are so speed concerned - then
perhaps you could try
http://search.cpan.org/~frew/DBIx-Class-0.08115/lib/DBIx/Class/ResultClass/HashRefInflator.pm
?

Z.

On Tue, Jan 12, 2010 at 10:26 AM, Ovid <publiustemp-dbic at yahoo.com> wrote:
> Relevant facts:
>
> 1.  bbc.co.uk is the fifth most popular web site in the UK (http://www.alexa.com/siteinfo/bbc.co.uk)
> 2.  We use DBIx::Class extensively on our iPlayer backend.
> 3.  Performance is critical.
>
> Code in our Web templates is not allowed to touch the database.  Thus, for each DBIx::Class result object, we extract the relevant data and put it into a simple object.  The relevant code looks like this:
>
>  sub _init_from_real_thing {
>    my $self = shift;
>
>    # from _real_thing
>    $self->$_( $self->_dbic->$_ ) for $self->attributes;
>
>    return $self;
>  }
>
> Creating one of these objects takes approximately 50 milliseconds. Each of the individual channels or episodes you see on http://www.bbc.co.uk/iplayer/ represents one of these blocks.  If we create 50 of these objects, that's 2.5 seconds -- way too long.
>
> As a performance hack, I'd like to experiment with something like this:
>
>  sub _init_from_real_thing {
>    my $self = shift;
>
>    my @attributes = $self->attributes;
>    @{$self}{@attributes} = @{$self->_dbic->{_column_data}}{@attributes};
>
>    return $self;
>  }
>
> Using the slices is a horrible encapsulation violation.  I can deal with that on our side, but not on the dbic side.  Is there a clean way of fetching all of that at once?
>
> If you're curious, here's my benchmark:
>
>             Rate methods   slice
>  methods 26954/s      --    -71%
>  slice   94340/s    250%      --
>
> Using the slice is almost four times faster than the "clean" strategy.
>
> Cheers,
> Ovid
> --
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>
>
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-- 
Zbigniew Lukasiak
http://brudnopis.blogspot.com/
http://perlalchemy.blogspot.com/