Friday, 14 June 2013

Database Management Systems SEt - I



1.
A collection of data designed to be used by different people is called a/an 
(a)
Organization
(b)
Database
(c)
Relationship
(d)
Schema
(e)
None of the above.
2.
Which of the following is the oldest database model?
(a)
Relational
(b)
Deductive
(c)
Physical
(d)
Network
(e)
Hierarchical.
3.
Which of the following schemas does define a view or views of the database for particular users?
(a)
Internal schema
(b)
Conceptual schema
(c)
Physical schema
(d)
External schema
(e)
Outer schema.
4.
Which of the following is an attribute that can uniquely identify a row in a table?
(a)
Secondary key
(b)
Candidate key
(c)
Foreign key
(d)
Alternate key
(e)
None of the above.
5.
Which of the following is the process of selecting the data storage and data access characteristics of the database?
(a)
Logical database design
(b)
Physical database design
(c)
Testing and performance tuning
(d)
Evaluation and selecting
(e)
External database design.
6.
Which of the following terms does refer to the correctness and completeness of the data in a database?
(a)
Data security
(b)
Data constraint
(c)
Data independence
(d)
Data model
(e)
Data integrity.
7.
The relationship between DEPARTMENT and EMPLOYEE is a
(a)
One-to-one relationship
(b)
One-to-many relationship
(c)
Many-to-many relationship
(d)
Many-to-one relationship
(e)
None of the above.
8.
A table can be logically connected to another table by defining a
(a)
Super key
(b)
Candidate key
(c)
Primary key
(d)
Unique key
(e)
Common attribute.
9.
If the state of the database no longer reflects a real state of the world that the database is supposed to capture, then such a state is called 
(a)
Consistent state
(b)
Parallel state 
(c)
Durable state 
(d)
Atomic state
(e)
Inconsistent state.
10.
Ensuring isolation property is the responsibility of the
(a)
Recovery-management component of the DBMS
(b)
Concurrency-control component of the DBMS
(c)
Transaction-management component of the DBMS
(d)
Buffer management component in DBMS
(e)
Query processor in DBMS.
11.
A transaction completes its execution is said to be
(a)
Committed
(b)
Aborted
(c)
Rolled back
(d)
Failed
(e)
Partially committed.
12.
The process of managing simultaneous operations on the database without having them interfere with one another is
(a)
Serializability
(b)
Recoverability
(c)
Concurrency control
(d)
Transaction management
(e)
None of the above.
13.
A schedule where the operations of each transaction are executed consecutively without any other interference from other transactions is called 
(a)
Non-serial schedule
(b)
Serial schedule
(c)
Recoverable schedule
(d)
Non-recoverable schedule
(e)
Concurrent schedule.
14.
Which of the following is not a deadlock handling strategy?
(a)
Deadlock prevention
(b)
Timeout
(c)
Deadlock detection and recovery 
(d)
Deadlock annihilation
(e)
None of the above.
15.
Which of the following does refer to the size of the data item chosen as the unit of protection by a concurrency control program?
(a)
Granularity
(b)
Lock
(c)
Starvation
(d)
Timestamp
(e)
Time based.
16.
Which of the following hashing techniques does allow a hash file to expand and shrink its number of buckets dynamically without needing a directory?
(a)
Linear hashing
(b)
Extensible hashing
(c)
Internal hashing
(d)
External hashing
(e)
Non-linear hashing.
17.
Which of the following indexes is based on the values being uniformly distributed using a mathematical function?
(a)
Ordered index
(b)
Hashed index
(c)
Dense index
(d)
Sparse index
(e)
Secondary index.
18.
A join in which the joining condition is based on equality between values in the common columns is called
(a)
Equi-join
(b)
Uni-lateral join
(c)
Natural join
(d)
Both (a) and (c) above
(e)
Both (b) and (c) above.
19.
A type of query that is placed within a WHERE or HAVING clause of another query is called
(a)
Master query
(b)
Query
(c)
Superquery
(d)
Multi-query
(e)
Subquery.
20.
The entity integrity rule states that
(a)
No primary key attribute can be null 
(b)
Referential integrity must be maintained across all entities
(c)
Each entity must have a primary key
(d)
A primary key must have only one attribute
(e)
Foreign key attribute can be Null.
21.
A named set of SQL statements that are considered when a data modification occurs are called
(a)
Stored procedures
(b)
Triggers
(c)
Packages
(d)
Trapdoors
(e)
Treatments.
22.
Which protocol ensures conflict serializability?
(a)
Value based protocol 
(b)
Read based protocol
(c)
Timestamp based protocol 
(d)
Validation based protocol
(e)
All (a), (b), (c) and (d) above.
23.
Which type of file is easiest to update?
(a)
Sequential
(b)
Hashed
(c)
Indexed
(d)
Clustered
(e)
B+ tree.
24.
When a regular entity type contains a multivalued attribute, one must
(a)
Create a single relation with multiple lines for each instance of the multivalued attribute
(b)
Create two new relations, one containing the multivalued attribute
(c)
Create two new relations, both containing the multivalued attribute
(d)
Crate three new relations
(e)
None of the above.
25.
Given following figure is an example of mapping which type of relationship?
(a)
First
(b)
Second
(c)
Unary
(d)
Ternary
(e)
Binary.
26.
A candidate key must satisfy all of the following conditions EXCEPT
(a)
The key must uniquely identify the row
(b)
The key must indicate the row’s position in the table
(c)
The key must be nonredundant

(d)
Each nonkey attribute is functionally dependent
(e)
One of the primary key.
27.
A relation that contains no multivalued attributes and has nonkey attributes solely dependent on the primary key, but contains transitive dependencies is in which normal form?
(a)
First
(b)
Second
(c)
Third
(d)
Fourth
(e)
Fifth.
28.
A functional dependency between two or more nonkey attributes is called a
(a)
Partial functional dependency
(b)
Partial nonkey dependency
(c)
Transitive dependency
(d)
Partial transitive dependency
(e)
Non transitive dependency.
29.
Which of the following technique is an alternative to log based recovery?
(a)
Check points
(b)
Locks
(c)
Page based
(d)
Recovery with current transactions
(e)
Shadow paging.
30.
DBMS periodically suspends all processing and synchronizes its files and journals through the use of
(a)
Checkpoint facility
(b)
Backup facility
(c)
Recovery manager
(d)
Database change log
(e)
Shadow paging.
31.
Data management is a discipline that focuses on
(a)   The management of end users
(b)   The proper generation, storage, and retrieval of data
(c)   The help items to be used by end users
(d)   The proper generation, storage, and retrieval of information
(e)   The management of data bases.
32.
The DBMS allows you to extrapolate information from your data by using
(a)   Query language                               (b)  Table generator                      (c)  Security system
(d)   Access control                                (e)  Program.
33.
One of the advantages of a relational database model is
(a)   Structural dependence                     (b)  Conceptual complexity
(c)   Complex database design               (d)  Easier database design                                                  
(e)   Structural independence.
34.
A DBMS performs several important functions that guarantee the integrity and consistency of the data in the database.  Which of the following is NOT one of those functions?
(a)   Data integrity                                  (b)  Storage management                   (c)  Data reports
(d)   Security management                      (e)  Data consistency.
35.
The most important advantages of the hierarchical database model are
(a)   Conceptual simplicity, security, integrity, diversity, and security
(b)   Security, efficiency, diversity, simplicity, and integrity
(c)   Integrity, efficiency, diversity, independence, and simplicity
(d)   Conceptual simplicity, security, hierarchy
(e)   Conceptual simplicity, security, independence, integrity, and efficiency.
36.
The most widely used conceptual model is the ______________.
(a)   E-R model                                      (b)  Chen model                              (c)  External model
(d)   Attribute model                               (e)  Use-case Model.
37.
The _____model represents a global view of the data.
(a)   Internal                                            (b)  External            (c)  Physical           
(d)  Conceptual                                      (e)  High-level.
38.
The ____ model operates at the lowest level of abstraction, describing how the data is saved on storage devices.
(a)   Internal                                            (b)  External            (c)  Physical           
(d)  Conceptual                                      (e)  View level.
39.
A ____ attribute is an attribute that can be further subdivided to yield additional attributes.
(a)   Composite        (b)  Simple              (c)  Single-valued     (d)  Multivalued        (e)  Derived.
40.
The entity integrity rule requires that
(a)   All primary key entries are not unique
(b)   A part of the key may be null
(c)   Foreign key values do not reference primary key values
(d)   Duplicate object values are allowed
(e)   All primary key entries are unique.
41.
A super key is any key that uniquely identifies each
(a)   Entity uniquely                                (b)  Object in a table                              (c)  Table
(d)   Structure in a table                          (e)  Column uniquely.
42.
A table can be logically connected to another table by defining a
(a)   Hyperlink                                        (b)  Common attribute                            (c)  Primary key
(d)   Candidate key                                 (e)  Super Key.
43.
A primary key that consists of more than one field is called a
(a)   Composite key                                (b)  Secondary key  (c)  Group key
(d)   All of the above                                                             (e)  None of the above.
44.
Which of the following statements concerning the primary key is true?
(a)   All primary key entries are unique
(b)   The primary key may be null
(c)   The primary key is not required for all tables
(d)   The primary key data does not have to be unique
(e)   For every primary key there must be a foreign key.
45.
In the context of a database table, the statement "A determines B" indicates that
(a)   Knowing the value of attribute A you can not look up the value of attribute B
(b)   You do not need to know the value of attribute A in order to look up the value of attribute
(c)   Knowing the value of attribute B you can look up the value of attribute A
(d)   Knowing the value of attribute A you can look up the value of attribute B
(e)   None of the above.
46.
A super key that does not contain a subset of attributes that is itself a super key is called a
(a)   Candidate key   (b)  Primary key                                     (c)  Super key
(d)   Secondary key  (e)  Foreign key.
47.
A table that displays data redundancies yields ____________ anomalies.
(a)   Update             (b)  Insertion                                          (c)  Deletion
(d)   All of the above                              (e)  None of the above.
48.
A table is in the Fourth Normal Form (4NF) if
(a)   All attributes must be dependent on the primary key, and must be dependent on each other
(b)   All attributes must be dependent on the primary key, but must be independent of each other
(c)   No row can contain two or more multivalued facts about an entity
(d)   A and C
(e)   B and C.
49.
A table where all attributes are dependent on the primary key and are independent of each other, and no row contains two or more multivalued facts about an entity, is said to be in
(a)   1NF                  (b)  2NF                  (c)  3NF                   (d)  4NF                  (e)  BCNF.
50.
The basic SQL aggregate function that gives the number of rows containing not null values for the given column is
(a)   MIN                  (b)  COUNT             (c)  MAX                 (d)  SUM                 (e)  AVG.

Answers


1.
Answer : (b)
Reason:  A collection of data designed to be used by different people is called a data base.
2.
Answer : (d)
Reason:  Network Model is the oldest database model.
3.
Answer : (d)
Reason:  External Schema define a view or views of the database for particular users.
4.
Answer : (b)
Reason:  Candidate Key following is an attribute that can uniquely identify a row in a table.
5.
Answer : (b)
Reason:  Physical database design is the process of selecting the data storage and data access characteristics of the database.
6.
Answer : (e)
Reason:  Data integrity refer to the correctness and completeness of the data in a database.
7.
Answer : (b)
Reason:  The relationship between DEPARTMENT and EMPLOYEE is a  one-to-many relationship.
8.
Answer : (c)
Reason:  A table can be logically connected to another table by defining a Primary Key.
9.
Answer : (e)
Reason:  If the state of the database no longer reflects a real state of the world that the database is supposed to capture, then such a state is called  in consistent state.
10.
Answer : (b)
Reason:  Ensuring isolation property is the responsibility of the  concurrency-control component of the DBMS
11.
Answer : (a)
Reason:  A transaction the completes its execution is said to be Committed.
12.
Answer : (c)
Reason:  The process of managing simultaneous operations on the database without having them interfere with one another is Concurrency control.
13.
Answer : (b)
Reason:  A schedule where the operations of each transaction are executed consecutively without any other interference from other transactions is called  Serial schedule.
14.
Answer : (d)
Reason:  Deadlock annihilation  is NOT a deadlock handling strategy.
15.
Answer : (a)
Reason:  Granularity refer to the size of the data item chosen as the unit of protection by a concurrency control program.
16.
Answer : (b)
Reason:  Extensible hashing techniques does allow a hash file to expand and shrink its number of buckets dynamically without needing a directory.
17.
Answer : (b)
Reason:  Extensible hashing techniques does allow a hash file to expand and shrink its number of buckets dynamically without needing a directory.
18.
Answer : (d)
Reason:  The equi-join is a join in which records are retrieved based on whether the join fields have matching values in both tables. That may seem like just a definition of a join, but it isn't. An example of a non-equal join is a join where records in the first table are joined to those records in the second table where the joined field in the first table is greater than (instead of equal to) the joined field in the second table (or less than, or anything besides equal to). Naturally, this returns more records than an equi-join.
              A natural join is one in which only one of the two tables’ joined fields is returned. Since these two fields are by definition identical in an equi-join, it is redundant to include both. For a non-equal join, it is important to include both of those fields. So, equi-joins and natural joins go together.
19.
Answer : (e)
Reason:  A type of query that is placed within a WHERE or HAVING clause of another query is called Sub query
20.
Answer : (a)
Reason:  The entity integrity rule states that no primary key attribute can be null
21.
Answer : (b)
Reason:  A named set of SQL statements that are considered when a data modification occurs are called triggers
22.
Answer : (c)
Reason:  Timestamp based protocol  ensures conflict serializability.
23.
Answer : (b)
Reason:  Hashed file is easiest to update.
24.
Answer : (b)
Reason:  When a regular entity type contains a multivalued attribute, one must Create two new relations, one containing the multivalued attribute.
25.
Answer : (d)
Reason:  The given mapping is an example of ternary relationship of Patient Treatment with three entities, viz., Patient, Physician and Treatment.
26.
Answer : (b)
Reason:  A candidate key (i) must uniquely identify the row
                                    (ii)    must indicate the row’s position in the table
                                    (iii)   must be non-redundant and
(iv)    (iv)     One of the primary key.
              A candidate key does not indicate the row’s positon in the table. Hence option (b) is the answer.
27.
Answer : (b)
Reason:  A relation that contains no multivalued attributes and has non-key attributes solely dependent on the primary key, but contains transitive dependencies is in second normal form.
28.
Answer : (c)
Reason:  A functional dependency between two or more non-key attributes is called a transitive dependency.
29.
Answer : (e)
Reason:  Shadow paging technique is an alternative to log based recovery.
30.
Answer : (a)
Reason:  DBMS periodically suspends all processing and synchronizes its files and journals through the use of Checkpoint facility.
31.
Answer : (b)
Reason : DBMS mainly focuses on the proper generation, storage, and retrieval of data
32.
Answer : (a)
Reason :        Query language is used to interact with the database        
33.
Answer : (d)
Reason: Relational data base helps us to design the data base in a easier manner.       
34.
Answer : (c)
Reason : Data reports is not a function of DBMS          
35.
Answer : (e)
Reason : The main important advantage of hierarchical data base model is conceptual simplicity, security, independence, integrity and efficiency
36.
Answer : (a)
Reason: Most widely used conceptual model is the E-R model.
37.
Answer : (d)
Reason : Conceptual model represents the global view of the data         
38.
Answer : (c)
Reason: Physical model operates at the lowest level of abstraction.      
39.
Answer : (a)
Reason : Composite attribute  can be further divided into additional attributes    
40.
Answer : (e)
Reason: All primary key entries are unique.   
41.
Answer : (a)
Reason : Super key is any key that uniquely identifies each entity uniquely         
42.
Answer : (b)
Reason : Common attribute is maintained to connect two tables logically
43.
Answer : (a)
Reason :        A primary key that consists of more than one field is called Composite key
44.
Answer : (a)
Reason: All primary keys are unique. 
45.
Answer : (d)
Reason : The answer is evident   
46.
Answer : (a)
Reason: The minimal set of super key is called candidate key.  
47.
Answer : (d)
Reason :        Table that displays data redundancies yields update, insertion, deletion anomalies       
48.
Answer : (e)
Reason :        The answer is evident
49.
Answer : (d)
Reason :        Answer is obvious
50.
Answer : (b)
Reason : Count function gives the number of rows containing not null values for the given column