Let’s assume that you have lots of tables that need to be dropped according to some criteria. Trying to do them all at once isn’t a good idea. Even with a powerful server it will either take forever or simply never finish.
For example – you may have millions of tables in sys.tables or millions of indexes you need to drop. SQL Server won’t process them well if you try to run it as one big statement.
I’ve never had millions of tables or millions of indexes to drop and now I am jealous. Regardless, Jeff has two techniques for us when you have a lot of work to do. And if you do need to figure out key dependencies, I have a script for that.