Three levels in database system architecture quiz

Relational model and Normalization Quiz

1. The layout of the data within the disk file system is found at the logical/conceptual level. TRUE / FALSE?

TRUE
FALSE

2. There is exactly one schema at the conceptual level for a database. TRUE/FALSE?

TRUE
FALSE

3. There is exactly one schema at the external level of a database. TRUE/FALSE?

TRUE
FALSE

4. A user’s access to the database can be limited by the schema at the external level. TRUE/FALSE?

TRUE
FALSE

5. The indexing schemes for each table is found at the external level. TRUE/FALSE?

TRUE
FALSE

6. The mappings between the levels provides for program-data independence. TRUE/FALSE?

TRUE
FALSE

7. The mapping between the external and logical levels provides various views to the users. TRUE/FALSE?

TRUE
FALSE

8. The levels in the architecture in sequence is logical-external-physical. TRUE/FALSE?

TRUE
FALSE

9. A physical schema is typically derived from the logical schema. TRUE/FALSE?

TRUE
FALSE

10. An Entity-Relationship model will map most closely to the logical schema. TRUE/FALSE?

TRUE
FALSE

Score =

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Quiz on normalization and functional dependency 6

Relational model and Normalization Quiz

1. Functional dependency analysis helps in the normalization of a relational schema. TRUE / FALSE?

TRUE
FALSE

2. Normalization attempts to reduce redundant information that are stored as part of a relation. TRUE/FALSE?

TRUE
FALSE

3. Redundancy is at the root of insertion and deletion anomalies in a relational database. TRUE/FALSE?

TRUE
FALSE

4. A null value has exactly one interpretation, ie., one meaning. TRUE/FALSE?

TRUE
FALSE

5. A functional dependency is a relationship between an attribute "Y" and a determinant (1 or more other attributes) such that for a given value of a determinant the value of the attribute Y is uniquely defined. TRUE/FALSE?

TRUE
FALSE

6. Functional dependencies can be found out algorithmically (automatically) by analysis of the relation. No semantic analysis is required. TRUE/FALSE?

TRUE
FALSE

7. In practical terms, we want non-key attributes to be functionally dependent on the primary key in any relation. TRUE/FALSE?

TRUE
FALSE

8. Transitivity of functional dependencies means that if a →b and a→c then c→b. TRUE/FALSE?

TRUE
FALSE

9. Decomposition of functional dependencies would mean that if a→bc then a→b and a→c. TRUE/FALSE?

TRUE
FALSE

10. Functional dependencies are reflexive, i.e., if a →b then b →a. TRUE/FALSE?

TRUE
FALSE

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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

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DBMS Basics and ER Model Quiz 7

Entity-Relationship Modeling Quiz 1

1. In a Entity-Relationship data model, an entity becomes a(n) _____________

Attribute
Table
Constraint
Column

2. The language that requires a user to specify the data to be retrieved without specifying exactly how to get it is

Procedural DML
Non-Procedural DML
Procedural DDL
Non-Procedural DDL

3. Which of the following data model is widely applied in many real world database applications?

Network model
Relational model
Hierarchical model
None of the above

4. The logical design of the database is database __________, a snapshot of the data in the database at a given instant in time is database ________.

Instance, Schema
Relation, Schema
Relation, Domain
Schema, Instance

5. The tuples (records) of the relations (tables) can be of ________ order.

Any
Ascending
Sorted
Descending

6. Which of the following is the collection of interrelated data and set of program to access them?

Data structure
Database
DBMS
Programming Language

7. Database management systems are intended to

Eliminate data redundancy
Establish relationships among records in different files
Manage file access
All of the above

8. ________________defines the database schema, Interacts continuously with users, defines integrity and security checks, defines procedures for backup and recovery

Sophisticated User
Naïve User
DBA
Application Programmer

9. The number of tuples in a relation is called __________ of a relation.

Cardinality
Degree
Tuple
Key

10. The number of attributes (columns) in a relation is called __________ of a relation.

Cardinality
Degree
Tuple
Key

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DBMS Basics and ER Model Quiz 6

Entity-Relationship Modeling Quiz 1

1. According to the levels of data abstraction, the schema at the intermediate level is called

Logical schema
Physical schema
Subschema
Conceptual schema

2. It is an abstraction through which relationships are treated as higher level entities

Generalization
Specialization
Aggregation
Inheritance

3. ___________ creates the metadata.

DML compiler
DML pre-processor
DDL interpreter
Query interpreter

4. When an E-R diagram is mapped to tables, the representation of which of the followig is redundant?

Weak entity sets
Weak relationship sets
Strong entity sets
Strong relationship sets

5. In an ER diagram, Y is the dominant entity and X is a subordinate entity. Then which of the following is incorrect?

Operationally, if X is deleted, so is Y
Operationally, if Y is deleted, so is X
Existence is dependent on Y
Operationally, if X is deleted, and remains the same

6. Which of the following can be considered as one of the reasons to model data?

Understand each user’s perspective of data
Understand the data itself irrespective of the physical representation
Understand the use of data across application areas
All of the above

7. In an ER Diagram, the concept total participation is represented by which of the following components?

Dashed lines between entity set and relationship set
Double lines between entity set and relationship set
Single line between entity set and relationship set
Solid line between entity set and relationship set

8. Relations (tables) that are produced by proper application of ER model will always be in

1NF
2NF
3NF
BCNF

9. "Manager salary details are hidden from the employee". Which of the following you can relate to this statement?

External level data hiding
Physical level data hiding
Conceptual level data hiding
None of the above

10. Which of the following two files are used during the operation of the DBMS?

Query languages and utilities
DML and query language
Data dictionary and transaction log
Data dictionary and query language

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Normalization and Functional Dependency - Quiz

1. A relationship R connecting entity sets E and F has referential integrity from E to F, i.e., the edge connecting R and F has an arrow directed towards F. Which of the following statements may be true?

R is one-one from E to F
R is many-one from E to F
Choice 2 only
Both choices 1 and 2

2. A relation with two attributes A and B satisfies the functional dependency A → B. Then the functional dependency B → A also holds in the relation.

TRUE
FALSE

3. A relation R(A,B,C) satisfies the functional dependencies A → B, A → C, and B → A. Then, we can say that R is in BCNF.

TRUE
FALSE

4. A relation R(A,B,C) satisfies the functional dependencies A → B, A → C, and B → A. Which of the following are valid candidate keys?

A
B
Both choices 1 and 2
A alone

5. Which of the following sentences are true??

4NF implies BCNF
4NF implies 3NF
3NF implies 4NF
Both choices 1 and 2

6. Assume that we have the following four records in a relation R(A, B, C): (1,2,3), (4,2,3), (5,3,3), and (5,3,4). Which of the following FDs does not hold on R?

BC → A
B → C
C → B
All of the above

7. For a relation R1(A,C,B,D,E), with dependencies A → B, and C → D which of the following is the candidate key?

{ABC}
{ACE}
{ADE}
{ABE}

8. The closure of set of attributes is said to be a set of ____________.

Functional Dependencies
Attributes
Keys
Multivalued Attributes

9. {A1, A2, …, An}+ is the set of all attributes of R if and only if A1, A2, …, An is a _______________ for R.

Prime attribute
Closure attributes
Super key
All of the above

10. Assume that the following set of FDs A → B, B → C, C → A, D → E, E → D are holding on a relation R(A,B,C,D,E). Which of the following sets of tuples satisfy this.

a1 b1 c1 d1 e1, a1 b1 c1 d2 e2
a1 b1 c1 d1 e1, a1 b2 c1 d2 e2
a1 b1 c1 d1 e2, a1 b1 c1 d2 e2
None of the above

Score =

Correct answers:

DBMS Basics - Quiz 5

DBMS Basics - Quiz 5

[Answers are given in Green color]

1. A relational database is said to be a group of ____.

a. common fields                                c. records

b. field values                                    d. tables

2. One of the advantages of a relational database model is ____.

a. structural dependence                     c. easier database design

b. conceptual complexity                    d. complex database design

3. Using network terminology, a relationship is called a(n) ____.

a. member                                 c. set

b. owner                                    d. table

4. The hierarchical database model is based on a ____.

a. tree structure                               c. lack of a child segment

b. lack of a parent segment                 d. Matrix

5. The hierarchical database model depicts a set of ____ relationships.

a. M:1                                               c. 1:M

b. 1:1                                                d. M:N

6. The hierarchical database is not very efficient when handling ____.

a. large amounts of data                     c. many transactions

b. few transactions                           d. 1:M relationships

7. The hierarchical database models ____.

a. have no implementation limitations          c. have very strict standards

b. promote database integrity                   d. have a simple navigational system

8. A relational database model ____.

a. does not require substantial hardware and system software overhead

b. does not promote "islands of information" problems

c. allows trained people to use a good system poorly

d. lets the user operate in a human logical environment

9. The network database models have a ____.

a. navigational system that yields simple design

b. simple system that promotes efficiency

c. relationship of owner/member that promotes database integrity

d. great deal of structural independence

10. Database models have been developed for ____.

a. modeling  real-world events or conditions     

b. depositing data within a single file

c. keeping data within multiple data repositories  

d. allowing DBMSs to maintain lose control over the database activities.

11. The RDBMS ____.

a. performs functions provided by the hierarchical and network DBMS system

b. does not manage data structures

c. allows the user/designer to ignore the logical view of the database

d. does not manage the details of physical storage

12. System’s complexity is hidden from the user and designer in RDBMS. This leads to ____.

a. it does not exhibit data independence

b. it does not exhibit structural independence

c. easier data management

d. data management is very difficult

13. Database models can be grouped into two categories:  conceptual models and ____ models.

a. implementation                             c. physical

b. logical                                   d. query

14. Every row/record in the relational table is called as an entity ____.

a. instance                                        c. attribute

b. relationship                                    d. model

15. Degree of ______ is a way to classify data models.

a. difficulty                                        c. abstraction

b. knowledge                                     d. unification

DBMS Basics Quiz

Database System Architectures - Quiz

1. What do you mean by Cardinality in Relational database?

Number of Tables
Number of Tuples (Records)
Number of Attributes
Number of Integrity Constraints

2. The view of a complete database is

Conceptual View
Physical View
Internal View
External View

3. In relational algebra, Cartesian product is ________________ operator.

an Unary operator
a Binary operator
a Ternary operator
All of the above

4. In Relational database, a relation is called as

Tables
Tuples
Attributes
None of the above

5. A database schema can be designed using which of the following languages?

DML
DDL
TCL
RDL

6. External level of the database system architecture is termed as

Logical Level
View Level
Conceptual Level

7. An entity set that does not have sufficient attributes to form a Primary key is _________

Simple entity set
Strong entity set
Weak entity set
Not an entity set

8. The DBMS language component which can be embedded in an application program is

DDL
DML
TCL
RDL

9. Which of the following is used in SQL to redefine/modify the definition of a table which already exists?

UPDATE
SET
ALTER

10. Relational Algebra is a ________________ language.

Data Definition Language
Procedural Language
Non-Procedural Language
Data Manipulation Language

Score =

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Database System Architecures and Distributed Database - Quiz 2

Distributed Database and Database System Architectures - Quiz

1. Which of the following is more suitable for parallelizing a single query?

Coarse-granularity parallelism
Fine-granularity parallelism
Both
None of them

2. A regular desktop machine (with two to four processors) can be mentioned as ________________ machine.

Fine-grain parallel
Coarse-grain parallel
Massively parallel
None of the above

3. If we parallelize the execution of large number of small transactions in a database system, then which of the following would be increased?

Response time
Rotational latency
Throughput
All of the above

4. If the speed of a parallel system is N when the larger system has N times the resources of the smaller system, then the speedup is __________

Linear Speedup
Sublinear Speedup
Superlinear Speedup
None of the above

5. Which of the following can affect the speedup and scaleup of a database system?

Startup costs
Interference
Skew
All of the above

6. Which of the following situation would cause a skew?

Huge amount of records in a table
Even distribution of records in multiple sites
Both
None

7. In which of the following architectures memory bus is not a bottleneck?

Shared memory and shared disk
Shared disk and shared nothing
Shared memory and shared nothing
All of the above

8. Which of the following would improve the availability of resources especially for reading in a distributed database system?

Fragmentation of database
Replication of database
Defragmentation of database
Tuning of database

9. ______________ is very much required to process a query in a distributed database.

Global System Catalog
Database Views
Triggers
None of the above

10. Reliability and availablity of a Centralized Data Allocation method is ___________ when compared to a Completely Replicated Data Allocation .

Highest
Average
Lowest
Not applicable

Score =

Correct answers:

Go to Distributed database home

Distributed Database - Quiz 1

1. Let us suppose that in a distributed database, during a transaction T1, one of the sites, say S1, is failed. When recovers, the site S1 has to check its log file (log based recovery) to decide the next move on the transaction T1. If the log contains a record, what the site S1 has to do?

Need not do anything
Perform Undo
Perform Redo
Abort the transaction

2. Global Wait-for graph is used for ________________ in Distributed database.

Handling concurrency control
Handling failures
Handling deadlock
None of the above

3. In Distributed database, ______________ are the transactions for which a log is found in the log file, but neither a log nor an log is found.

In-doubt transactions
Serialized transactions
Cascadeless transactions
Distributed transactions

4. While using commit protocols for handling atomicity issues, the distributed database system may enter into a situation called Blocking problem. Which of the following commit protocols can avoid Blocking problem?

Two-phase commit protocol
Three-phase commit protocol
Both of the above
None of the above

5. Which of the following concurrency control protocol is suitable for an application where frequency of read operation is much greater than that of write operation?

Majority protocol
Quorum-consensus protocol
Biased protocol
Single lock protocol

6. Which of the following parallel database architectures is/are mainly used by distributed database system?

Shared Memory
Shared Disk
Shared Nothing
Hierarchical

7. Which of the following is not a promise of distributed database?

Network Transparency
Replication Transaparency
Fragmentation Transparency
None of the above

8. All sites in a distributed database must commit at exactly the same instant. TRUE/FALSE

TRUE
FALSE

9. The real use of the Two-phase commit protocol is ______________

Deadlock will not occur
Concurrency control can be avoided
Atomicity, i.e, all-or-nothing commits at all sites
None of the above

10. Read one, write all available protocol is used to increase ___________ in a distributed database system.

Availability
Robustness
Both Availability and Robustness
Neither Availability nor Robustness

Score =

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