Hi Perl Monks, The following code "Works" but I don't think it should. Can anyone explain why the code seems to work and does not give me random memory garbage? My program is eating up a lot of memory using this code and I am trying to find a way to store this data on disk, but using Tie or other methods doesn't seem to take the referenced array data into account..only the array references(being scalar and all that) - Anyway - here is some summarised code with the few specific lines detailed in full: 
my %bigHash
my @Arraybits

do this a few times
{

      @Arraybits = ["data","that","is","unique", "for","each","loop"];

      my @tmparray = @Arraybits;

      until (We have done this a few times)
      {

          push @{ $bigHash {$Key} }, \@tmparray; 
    
          #OR push @{ $bigHash {$Key} }, [@tmparray];

      }

@tmpxmlarray = [];
undef (@tmpxmlarray);
}

[download]
This code eats up memory really quickly. I put about 80,000 arrays into the hash this way. When I debug it I can see the full data set in the Hash and work on it whilsts the program is running However, if I tie the Hash to a DB_File or other db...I seem only able to store the array references on Disk..and my RAM still fills up, storing what I assume is all the array content. I would have thought that if I use undef, the data would be marked as feww in memory again...but al the array content is available...I just can't seem to get it out of RAM and onto disk. Any suggestions on an easy way to move this Hash of Arrays to disk including the array data and avoid eating up RAM?

In reply to Hash of Arrays - Pushing Array references and memory impacts question by alittlebitdifferent

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