Happy to find the link to an earlier discussion on this matter. The advice given is exactly what I was looking for. However, given the number of people I have, I am still reluctant to go ahead with the 'sync' process at this time. I will work on my database and try to put it in proper order before I attempt any 'sync'ing.
I think I will split off a part of my tree and try it on a small scale before attempting anything huge like forty thousand people.
I do thank all those who replied in an effort to help me.