my $dbh = DBI->connect ("dbi:CSV:", undef, undef, {
    f_dir      => "DEMO.db:",
    f_ext      => ".csv/r",
    f_schema   => undef,
    PrintError => 1,
    RaiseError => 1,
    });
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The disadvantage of this when the data set grows bigger is that all of your CSV data is kept in memory, and probably even twice. That, plus some meta-data will quickly gobble up most of your available valuable memory. If you want an intermediate database to make a move to something real later on, and still want portability, skip DBD::CSV and use DBD::SQLite instead. It is lightweight, fast and portable and supports a lot more than CSV.