Thank you very much. Your statements helped me a lot. I see that at the second run, no new symbols will be added to the symbol-table. But why the memory is increased by 548 KB? 
    use XML::Simple;
    use Devel::Symdump;

    Devel::Symdump->rnew(); # init

    CProcess->PrintProcessInfo("perl.exe");
    
    {
        my $xs  = new XML::Simple();
        my $root= $xs->XMLin('D:\xTools\test\xmltest.xml');
    }
    CProcess->PrintProcessInfo("perl.exe");

    my $dump = Devel::Symdump->rnew();

    {
        my $xs  = new XML::Simple();
        my $root= $xs->XMLin('D:\xTools\test\xmltest.xml');
    }
    CProcess->PrintProcessInfo("perl.exe");
    print "---------\nAdded new to symbol-table:\n";
    print $dump->diff(Devel::Symdump->rnew());
    print "---------\n";

[download]

Process-ID 9372: Memory 34952 KB (+34952 KB) - Peak 34952 KB - Threads 3 - Handles 118 (perl)

Process-ID 9372: Memory 133784 KB (+98832 KB) - Peak 145704 KB - Threads 3 - Handles 118 (perl)

Process-ID 9372: Memory 134332 KB ( +548 KB) - Peak 146596 KB - Threads 3 - Handles 118 (perl)

---------

Added new to symbol-table:

---------

In reply to Re^2: How can I free the memory of a XML::Simple-Object by Bauldric
in thread How can I free the memory of a XML::Simple-Object by Bauldric

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