For whatever it's worth...I think I found why the performance was so slow in VB.NET vs. Foxpro.

In my Foxpro Applications, I have a routine to show the progress of the batch update. I do this by showing the record numbers in textboxes or labels such as "Processing record number X of Y".

In my rewrite in VB.NET, I did the same thing to show progress because some of the files are rather large and instead of wondering if the program is stuck, I like to show some type of activity. So, once again, I incorporated the "Processing record number X of Y" routine.

What I discovered, at least in my case, that if I show each record number in sequence (1 of 600000, 2 of 600000, 3 of 600000, etc) this kills the performance. Most of you probably already instinctively knew that. But, I'm new at this.

Instead of showing each individual number, I altered the code to show progress every 500 records. This cut processing time down from around 7 hours to maybe an hour or so. When I changed my refresh rate to every 1000 records, it cut the processing some a little more. When I only show progress every 100,000 records, it completes within 20 minutes.

Like I said, for whatever it's worth, altering a small 'display progress' routine did the trick for me.