#!/usr/bin/perl
use strict;
use warnings;
use Config::IniFiles;
my $cfg;
BEGIN {
  $cfg = new Config::IniFiles( -file => 'settings.ini' );
  $ENV{_MyCDBI} = join("\t",
    $cfg->val('Database', 'dsn'),
    $cfg->val('Database', 'Username'),
    $cfg->val('Database', 'Password')
  );
}
use MyCDBI;

##</code><code>##

my $cfg = new Config::IniFiles( -file => 'settings.ini' );
$ENV{_MyCDBI} = join("\t",
  $cfg->val('Database', 'dsn'),
  $cfg->val('Database', 'Username'),
  $cfg->val('Database', 'Password')
);
require MyCDBI;

##</code><code>##

package MyCDBI;
use base 'Class::DBI::mysql';
__PACKAGE__->connection(split("\t", $ENV{_MyCDBI}));

##</code><code>##

my $obj = MyCDBI::SomeDBObj->retrieve(1);
# versus
my $cls = new MyCDBI;
my $obj = $cls->SomeDBObj->retrieve(1);