DSXchange

But with sequential (text) files you need to specify how NULL is represented. Text files don't really have data types - they only contain text. And with fixed-width format text files, the representation of NULL must have the same number of characters as any non-null value in that particular field (subset of character positions).

That is a limitation of Datastage. I use a few of the bulk loader utilites directly and these can use sequential files without corrupting my data. I can use Datastage as well, but I have to change chars to varchars because it thinks my data needs to be how it needs to represent it. WRONG. I don't want to corrupt my data so that I must de-corrupt it later. A waste of computer resources.