How can I make sure that SaveChanges executes its statements in a certain order

Among other CRUD things I have to make a deletion on table X for a certain timespan. If this deletion is sucessfully I have to insert data in table X for the same timespan. If the nonqueries run the other way round first Insert second deletion that would be totally wrong.

How can I make sure the order of execution?

You can cover this by having explicit SaveChanges calls for each action. e.g.

// remove from table X for a certain timespan
UnitOfWork.SaveChanges(true);

// add new entities
UnitOfWork.SaveChanges();

In particular if you are going to remove by query you will want to ensure you call SaveChanges or dispose your UnitOfWork after that call to avoid dirty state. See the notes under Considerations for Bulk Operations here: http://www.mindscapehq.com/documentation/lightspeed/Performance-and-Tuning/Bulk-Updates-and-Deletes

Jeremy