Exercise 16.9 Consider a database with the following schema:Suppliers(sid: integer, sname:...

Exercise 16.9 Consider a database with the following schema:

Suppliers(sid: integer, sname: string, address: string)
Parts(pid: integer, pname: string, color: string)
Catalog(sid: integer, pid: integer, cost: real)

The Catalog relation lists the prices charged for parts by Suppliers.

Consider the transactions T1 and T2. T1 always has SQL isolation level SERIALIZABLE. We first run T1 concurrently with T2 and then we run T1 concurrently with T2 but we change the isolation level of T2 as specified below. Give a database instance and SQL statements for T1 and T2 such that result of running T2 with the first SQL isolation level is different from running T2 with the second SQL isolation level. Also specify the common schedule of T1 and T2 and explain why the results are different.

1. SERIALIZABLE versus REPEATABLE READ.
2. REPEATABLE READ versus READ COMMITTED.
3. READ COMMITTED versus READ UNCOMMITTED.