Question#1: Why locking is mandatory for ensuring consistency?[explain briefly in your own words with example] Question#2: Why is Two-Phase locking preferred over simple Locking? Explain with example...

Question#1:

Why locking is mandatory for ensuring consistency?[explain briefly in your own words with example]

Question#2:

Why is Two-Phase locking preferred over simple Locking? Explain with example of your own.[explain briefly in your own words with example]