I am working on a solution that includes some potentially very lengthy exports ( as in hours). This solution requires me to keep track of the last time the data was moved, i. e. I will store a timestamp so I can pick up the changed data next time. Now I am wondering if I need to safe that timestamp before or after the export. I assume before but would love to hear from you. Especially interesting: what happens if the data is changed during the export? Does the export consider that?