JNTU II B.Tech I Semester Supplimentary Examinations, November 2008
DATA BASE MANAGEMENT SYSTEMS
( Common to Computer Science & Engineering, Information Technology
and Computer Science & Systems Engineering)SET-1
1. (a) Describe about the three levels of Data Abstraction.
(b) What are the types of languages a database system provides? Explain.
2. (a) What is a relation? Differentiate between relation schema and relation instance. Define the terms unity and degree of relation. What are domain constraints?
(b) Explain new insertion, delation and updating of database is performed in the relational algebra.
3. (a) explain about decomposition?
(b) Suppose the schema R(A,B,C,D,E) is decomposed into (A,B,C) and (A,D,E)
show that the decomposition is not a dependency preserving decomposition if the following set of FD hold ABC, CDE, BD, EA.
4. Explain the 4NF. Why is it useful? Explain with example
5. (a) Write a short notes on
(b) Why must lock & unlock be atomic operation?
6. (a) State & justify the Thomas write rule.
(b) Describe each of the following locking protocols
ii. Conservative 2PL
7. In the sequential file organization, why is an overflow block used even if there is, at the moment, only one overflow record?
8. Suppose that we are using extendable hashing on a file that contains records with the following search-key values: 2,3,5,7,11,17,19,23,29,31 Show the extendable hash structure for this file if the hash function is h(x) = x mod 8 and buckets can hold three records.