Thanks for your response. I had read those pages and tried using all sorts of combinations of DataGen, Properties and Groovy script in my effort to make it work.
I finally have made it work just a bit ago but not in the way that I was asking. I changed the SQL in the DataSource to < 11 rows, instead of just 1. The JDBC Request still is limited to 1 row. The DataLoop causes my test case to process the 10 rows, one at a time, successfully.
I would still like to know if there is any way to programmatically set the number of rows in a DataSource.