my $g_cpu = Proc::Governor->new( { maxPercent => 80 } );
    my $g_db =  Proc::Governor->new( { maxPercent => 30 } );

    $g_db->beginWork();
    my $db = DBI->connect( ... );       # DB work
    my $rows = $db->selectall_arrayref( ... );
    $g_db->endWork();

    for my $row ( @$rows ) {
        my $upd = $g_cpu->work( sub {
            process_row( $row );        # Local work
        } );
        $g_db->work( sub {
            $db->update_row( $upd );    # DB work
        } );
    }