Date's Twelve Rules for Distributed Database Systems - Operating System Independence

Date's Twelve Rules for Distributed Database Systems - Operating System independence / DDBS should support OS independence

Be able to run the same DDBMS on different operating system platforms.

This is applicable for a database spread over multiple servers. The transaction management system should be able to handle a single transaction where data are part of multiple different servers running on different platforms.

Figure 1

Observe from the above diagram that the server at different locations run on different operating systems. If a database is spread over these different servers, the DDBMS must be able to handle all the parts of the database in a way irrespective of Operating systems.

In this example, the University database partitions at multiple locations should be accessible by a DDBMS without any OS related issues. 

Database Management Systems - Cochin University November 2009 Questions

Database Management Systems - Cochin University November 2009 Questions / CUSAT - DBMS Nov 2009 Question / CS 505 DBMS CUSAT Question

BTS (C) – V – 09 – 055 – G

B.Tech Degree V Semester Examination, November 2009

CS/IT 505 Database Management Systems

(2006 Scheme)

Time: 3 Hours                                                    Maximum marks: 100

PART – A

(Answer ALL Questions)

 (8 X 5 = 40)

I. (a) What is meant by data abstraction? How it helps to provide data independence?

(b) With suitable example, explain ‘partial key’ and ‘primary key’ concepts.

(c) Are tuples in a relation ordered? Why? What do you mean by domain of attributes?

(d) Describe the concept of functional dependencies with an example. When it will be trivial?

(e) Describe ACID properties of transactions. State its significance also.

(f) Explain the goals of data mining.

(g) Explain the technique ‘hashing’. Distinguish between internal and external hashing.

(h) Why do we use spanned records? Mention advantages and disadvantages.

PART – B

 (4 X 15 = 60)

II. (a) Explain the 3-schema architecture of database system. How it helps to achieve data independence? (7)

(b) Why do we use constraints in ER model? Describe various constraints. (6)

(c) When is super class/sub class relationship needed in data modeling?

OR

III. An University with various departments keep track of student details. Each ‘department’ runs courses (with unique course#) and each ‘course’ is divided into ‘sections’. Each section has a (coordinator, semester, year, course). Grade reports are supplied to students. Design an ER schema for this, supplying necessary attributes. Draw ER diagram and specify key attributes of each entity type and structural constraints on each relationship. (15)

IV. (a) When does collision occur in hashing? What are the resolution methods? (5)

(b) Why do we use ‘indexes’ in file access? (2)

(c) Explain any two single level ordered indexes. (8)

OR

V. (a) What is ‘mixed file’? Write difference between fixed length and variable length records. (5)

(b) Explain any two dynamic hashing techniques. (10)

VI. (a) A company database is given below;

          EMPLOYEE (NAME, ENO, DOB, SALARY, SEX, SUPERENO, DNO)

          DEPARTMENT (DNAME, DNUMBER, MGRENO, STRTDATE)

          DEPTLOCATIONS (DNUMBER, DLOCATIONS)

          PROJECT (PNUMBER, PLOCATION, DNUM)

          WORKS-ON (EENO, PNO, HOURS)

Write the following queries in SQL;

          (i) Retrieve all employees in department 1 whose salary is between 25,000 and 40,000.

          (ii) Get a list of employees and projects they are working on, ordered by department.

          (iii) For each employee, get the name and address of the manager.

          (iv) Get DOB and address of employees with name ‘James’. (8)

(b) Explain the use of various ‘JOIN’ operators in relational algebra. (3)

(c) Describe first 3 normal forms with examples. (4)

OR

VII. (a) Discuss various relational model constraints. (10)

(b) What is the need for high level data model? (2)

(c) Write the difference between ‘left outer join’ and ‘right outer join’ operations. (3)

VIII. (a) What are the problems associated with uncontrolled concurrent transactions? (6)

(b). Explain any two concurrency control techniques. (9)

OR

IX. (a) Discuss the relation of data mining to knowledge discovery. (7)

(b) Write short notes on object oriented databases and active databases. (8)

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Relational model and Normalization Quiz 5

Relational model and Normalization Quiz

1. One or more columns of a composite primary (a primary key that comprises of more than one attribute) key can be allowed to have NULL values. TRUE / FALSE?

TRUE
FALSE

2. A foreign key of any table must refer to the primary key of its base table. TRUE/FALSE

TRUE
FALSE

3. The value of a foreign key attribute A of table R that refers to table S cannot be NULL if which of the following holds?

If attribute A is part of a primary key attribute in R
If attribute A refers the primary key of S
If attribute A is UNIQUE
If either a or b or both holds

4. An attribute must contain only values consistent with the defined data format of that particular attribute is called

Entity integrity
Referential integrity
User-defined integrity
Column integrity

5. The __________ property ensures that any instance of the original relation can be identified from corresponding instances of the smaller relations.

Lossless-join
Lossy-join
Both a and b
None of the above

6. In a functional dependency AB --> C, which of the following is true?

A is Determinant of C
B is Determinant of C
Both A and B together Determine C
All of the above

7. Which of the following is also called as Subset dependencies?

Entity integrity constraints
Referential integrity constraints
User-defined integrity constraints
Column integrity constraints

8. The determinant of a functional dependency refers to the attribute, or group of attributes, on the left-hand side of the arrow.

TRUE
FALSE

9. Assume a set of functional dependencies F = {Regno Name --> Gender, Regno --> Department, Regno --> Gender, Name --> Branch}. Here, Regno Name --> Gender is,

Gender is fully funcionally dependent on Regno and Name
Gender is partially funcionally dependent on Regno and Name
Name and branch together form the primary key
None of the above

10. _____________ ensure that a value that appears in one relation for a given set of attributes also appears for a certain set of attributes in another relation.

Referential integrity constraints
Weak entity sets
Entity integrity constraints
None of the above

Score =

Correct answers:

Database Management Systems University Question 8

Database Management Systems (DBMS) University Question 8

Database Management Systems

Time : Three Hours                                                                          Max.Marks:100

Answer ALL Questions

(10 X 10 = 100 Marks)

1. a) What are the responsibilities of the DBA and the database designers? [3]

b) What are the different types of database end users? Discuss the main activities of each [4]

c) Discuss the capabilities that should be provided by a DBMS. [3]

2. a) Describe the three-schema architecture. Why do we need mappings between schema levels?  How do different schema definition languages support this architecture? [4]

b) Write a short note on component modules of an DBMS with neat diagram. [6]

3. a) Define the following terms: composite attribute, multivalued attribute, derived attribute, complex attribute, key attribute, value set (domain). [6]

b) Discuss the entity integrity and referential integrity constraints. Why is each considered important? [4]

4. a) List the operations of relational algebra and the purpose of each. [4]

b) Consider the following schema: [6]

Suppliers(sid: integer, sname: string, address: string)

Parts(pid: integer, pname: string, color: string)

Catalog(sid: integer, pid: integer, cost: real)

Write the following queries in relational algebra

1. Find the pnames of parts for which there is some supplier.

2. Find the snames of suppliers who supply every part.

3. Find the snames of suppliers who supply every red part

5. Notown Records has decided to store information about musicians who perform on its albums (as well as other company data) in a database. The company has wisely chosen to hire you as a database designer (at your usual consulting fee of $2500/day). Each musician that records at Notown has an SSN, a name, an address, and a phone number. Poorly paid musicians often share the same address, and no address has more than one phone. Each instrument used in songs recorded at Notown has a unique identification number, a name (e.g., guitar, synthesizer, flute) and a musical key (e.g., C, B-flat, E-flat).Each album recorded on the Notown label has a unique identification number, a title, a copyright date, a format (e.g., CD or MC), and an album identifier. Each song recorded at Notown has a title and an author. Each musician may play several instruments, and a given instrument may be played by several musicians. Each album has a number of songs on it, but no song may appear on more than one album. Each song is performed by one or more musicians, and a musician may perform a number of songs. Each album has exactly one musician who acts as its producer. A musician may produce several albums, of course. Design a conceptual schema for Notown and draw an ER diagram for your schema. Be sure to indicate all key and cardinality constraints and any assumptions you make. Identify any constraints you are unable to capture in the ER diagram and briefly explain why you could not express them.

6. a) What is Normalization? Explain Normalization techniques using functional dependencies with relevant examples. [7]

b) Consider the relation schema R(A,B,C,D,E, F,G,H) with functional dependencies

F = {BE → GH, G → FA, D → C, F → B}.

(a) Find a (minimal) key for R. [3]

7. Write a short note on the following

1. Storage and file structure

2. Indexed files Vs Hashed files;

3. B-trees;

8. a) Differentiate between the following: with example In SQL queries [5]

(i) Theta Join. (ii) Equi Join. (iii) Natural Join (iv) Outer Join.

b) Discuss the entity integrity and referential integrity constraints. Explain constraint Violations during update operations? [5]

9. Explain the following protocol to ensures conflict serializability

a) locking protocols,

b) timestamp ordering protocol

10. a) State the types of failures that may occur in a system. [3]

b) Explain log based recovery with respect to Deferred Database Modification and Immediate Database modifications. [7]

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