Transactions and concurrency control

Question 1
A
Only S1 is conflict-serializable.
B
Only S2 is conflict-serializable.
C
Both S1 and S2 are conflict-serializable.
D
Neither S1 nor S2 is conflict-serializable.
       Computer Networks       Transactions and concurrency control       Gate 2014 Set -03
Question 1 Explanation: 
S1:

No cycle, so schedule S1 is conflict serializable.
S2:

There is a cycle, so S2 is not conflict serializable.
Question 2
Which level of locking provides the highest degree of concurrency in a relational database?
A
Page
B
Table
C
Row
D
Page, table and row level locking allow the same degree of concurrency
       Database Management System       Transactions and concurrency control       Gate 2004-IT
Question 2 Explanation: 
In page level locking, it will lock whole page i.e., all rows are highly restrictive.
Table locking can be used for concurrency control with DDL operations.
In row share table is less restrictive but it consists of highest degree of concurrency compared to page and table.
There are 2 questions to complete.