see Q&A How do i create array of arrays

Your sample code required some interpretation. Feel free to correct me.

my @_STORAGE;

sub recursive_store {
   $query[$level] = "SELECT ...";
   my $sth = $dbh->prepare($query[$level]);
   $sth->execute;
   $_STORAGE[$level]= $sth->fetchall_arrayref;
   $sth->finish();
}

&recursive_store($level);

# Example access:
print _STORAGE[$level][$row][$col];

# Show what we have:
use Data::Dumper;
print Dumper \@_STORAGE;
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Thanks a lot for your code. I need to apologize for not using it, because I ended up with my own solution. What I do now is instead of storing the whole array, I just shift the value off and store it in a hash table. In other words I am using parallel arrays with identical subscripts, and this seems to work fine recursing over the whole structure.

But I'll add a bookmark to your solution because it does answer the question by storing the reference to the array. Thanks!

Just for laughs, here is my code. I am recursing through 6 levels this way, but I feel it will work for any number of levels:

$query[$level]->execute;
while((@level_data)=$query[$level]->fetchrow_array) 
    {
    %treepos = (); # reset the whereclause for a new branch
    %pathpos = ();
    
    $treepos{$key} = shift @level_data;
    $pathquery[$level] = &path_sql($childlevel,$treepos{$key});
    while((@path_data)=$pathquery[$level]->fetchrow_array) 
        {
        $pathpos{$key} = shift @path_data;
        &level_proc;
        }
    }
    
    sub level_proc {
        $query[$childlevel] = &level_sql($childlevel,$treepos{$key});
        while((@level_data)=$query[$childlevel]->fetchrow_array)
        {
        &setlevel($childlevel);
        $treepos{$key} = shift @level_data;
        &path_proc;
        $treepos{$key} = undef;
        &setlevel($parlevel);                            
        }    
    sub path_proc {
        $pathquery[$level]= &path_sql($pathpos{$parkey},$treepos{$key}
+);
        while((@path_data)=$pathquery[$level]->fetchrow_array)
        {
        $pathpos{$key} = shift @path_data;
        &children_proc;
        }
        
    }
    }
    sub children_proc {
        &children_sql($pathpos{$key},$childlevel);
        &level_proc;
    }
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I'm not sure what you are doing. Actually, I have no clue what you are doing, and I can't figure out without the missing functions. But I do know this code will be a nightmare to maintain. Requiring 8 functions (children_proc children_sql, level_proc, level_sql, path_proc, path_sql, setlevel and the block outside the functions) to populate a structure from a database is a sure sign something is wrong. If you want some help, please specify what you want for output (what you want your structure to look like).