As of December 1, 2020, Focal Point is retired and repurposed as a reference repository. We value the wealth of knowledge that's been shared here over the years. You'll continue to have access to this treasure trove of knowledge, for search purposes only. Moving forward, myibi is our community platform to learn, share, and collaborate. We have the same Focal Point forum categories in myibi, so you can continue to have all new conversations there. If you need access to myibi, contact us at email@example.com and provide your corporate email address, company, and name.
I received this information from a project manager regarding your question:
The SQLIN is not a real file. The output from the select statement (SQLIN) becomes the input to a modify, without ever getting written to disk as a file. If you want an intermediate flat file, you could always disable automatic pass through, slowing things down a bit.