Let’s just imagine a World without intent locks for a moment. In that World, a user has just decided to select a row from our database. SQL at that point is going to put down a shared lock against the row.
Now what’s going to happen when another user decides to modify a bunch of rows? Now because of the number or rows involved in this modification, SQL is going to want to take out an exclusive page lock. Where’s the issue here?
Read on to learn what the issue is.