app->attr(dbh => sub {

   my $self = shift;
   my $dsn  = 'dbi:Oracle:schema';
   my $usr  = 'Scott';
   my $pas  = 'tiger';
   my $dbh  = $DBI->connect_cached( $dsn, $usr, $pas );

   return $dbh;
}

# later

get '/query' => sub{

   my $c = shift;
   my $dbh = $c->app->dbh;
   my $sql = 'SQL QUERY HERE';
   my $sth = $dbh->pepare_cached( $sql );
   my $details = $dbh->selectall_arrayref( $sql, { Slice = {} });

  # and so on
};