While I wrote SQL::Type::Guess, it really, really wants to have all the data in memory already, which is asking a bit much for a 5 TB file.

If you are content with a quick approach, consider either taking the first 100 GB or a random sampling of rows from your input file(s) and use these with SQL::Type::Guess to determine good types for your columns.

Alternatively, a more "manual" approach of reading the file line by line and feeding the information to SQL::Type::Guess could also work:

while (my $hashref = read_next_row_from_file_as_hashref( $fh )) {
    $sqltypes->guess( $hashref );
}

[download]

Have you looked at how long it takes to read the 5TB file without doing any processing? Maybe two days isn't all that bad.

In reply to Re: Possible faster way to do this? by Corion
in thread Possible faster way to do this? by Anonymous Monk

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