DATABASE MANAGEMENT SYSTEM

Serializability of concurrent transaction is ensured by

• (i) locking
• (ii) time stamping
• (iii) both (a) and (b)
• (iv) none of these

Which of the following is true?

• (i) B+ tree allows only the rapid random access
  (ii) B+ tree allows only the rapid sequential access
  (iii) B + tree allows rapid random access as well as rapid sequential access
  (iv) B + tree allows rapid random access and slower sequential access

Transaction processing is associated with everything below, except

• (i) conforming an action or triggering a response
  (ii) producing detailed summary or exception report
  (iii) recording a business activity
  (iv) maintaining a data

f) To which of the following term “DBA” referred?

• (i) Data Bank Administrator 
• (ii) Data Administrator 
• (iii) Database Administrator 
• (iv) None of the above

What are the differences between primary index and secondary index?

Explain two-phase locking protocol & conflict serializability. | Unit 3 – Transaction Management | Concurrency control.

How does the remapping of bad sectors by disk controllers affect data retrievals rates?

Show that the two-phase locking protocol ensures conflict serializability and that transaction can be serialized according to their lock points.

Explain ACID properties.

Consider the following ordering schedule —
S’ of transactions:

T1 : R(A);  
T1 : A := A + 5;  
T1 : commit;  

T2 : R(B);  
T2 : B := B + 5;  

T3 : R(C);  
T3 : C := C + 5;  
T3 : C := C + 5;  

T4 : R(A);  
T4 : A := A + 5;  
T4 : R(D);  
T4 : D := D + 5;  
T4 : commit;  

T2 : commit;  
T3 : commit;

Let the initial value of A = B = C = D = 0.
The system follows log-based recovery process of immediate database modification.

The assumption is the concurrency control system uses strict 2PL, and all transactions share a common disk buffer and single log.

Explain what happens during the recovery process if a failure occurs at T2 : commit statement.

What do you mean by concurrency control techniques?

Write a short note on any one of the foflowing:

• (b) Database recovery