Maybe I'm just delusional, but I was under the impression that when using DBI that calling using the execute,prepare,fetch technique meant that the table was retrieved piecewise, as in one row at a time. If you were bold enough to use something like fetchall_arrayref() instead, then you would expect the entire thing to appear in RAM. I haven't been able to find any clarification on the internals of DBI with respect to this particular aspect.

I'm doing something pretty simple on a 9M row table, and yet DBI is chomping up a good 300MB+ of RAM if you should let it run that long:

        use DBI;

        # (Init w. AutoCommit=>1 occurs here)

        # Prepare the SELECT statement...
        my ($s)    = $db->prepare ("SELECT * FROM table");

        # ...and run it.
        my ($s_rv) = $s->execute();

        # Wait patiently, run out of RAM...

        # Presumably, should be able to fetch data and use it here:
        while (my @row = $s->fetchrow_array()) { ... }
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I'm not making it past the $s->execute() statement, and I don't want to make a trip to RAM Depot^® for a bulk purchase.