NR

Code No: NR311202

in

III B.Tech I Semester Supplimentary Examinations, May/Jun 2009 DATABASE MANAGEMENT SYSTEMS (Information Technology) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Explain about various binary operations with examples in relational algebra.

[12+4]

ld .

(b) Discuss the use of rename operator with an example.

2. (a) What are views? Discuss the problems encountered in modifying database through views. (b) What is an embedded SQL? Give examples.

[10+6]

3. (a) Explain the sequential flooding of the buffer pool.

[8+8]

or

(b) When does a buffer manager write a page to disk.

uW

4. (a) Consider the following SQL query for a bank database SelectT.branch − name F rombranchT, branchS whereT.Assets ¿ S.assetsandS.branch − city = ”HY DERABAD00 Write an efficient relational algebra expression that is equivalent to the query. (b) Define query optimization and at what point during query processing does optimization occur? [8+8] 5. (a) At what point during query processing does optimization occur.

nt

(b) Consider the following SQL queries for a bank DB select T.branch name from branch T,branch S where T.assets> S.assets and S.branch city = ”Chennai” Write an efficient relational-algebra expression that is equivalent to this query. Justify

Aj

(c) What is multiple equivalence. How is multiple transformation done by the following query? Πcustomer name ( σbranch city = ”Chennai”(branch X (account X depositor))) [4+6+6]

6. (a) Let R=(A,B,C,D,E) and let M be the following set of multivalued dependencies A− >> BC B− >> CD E− >> AD List the nontrivial dependencies in M+ (b) Describe the properties of normalized and unnormalized relations. 1 of 2

[10+6]

NR

Code No: NR311202 7. (a) Explain the concept of log based recovery. (b) Briefly explain why recovery is needed.

[10+6]

8. Describe the shadow paging recovery technique. Under what circumstances does it not require a log. [16]

Aj

nt

uW

or

ld .

in

?????

2 of 2