1: Incase of Context-level Diagram, the system is represented by
- One process atleas
2:Two processes atleast
3: One process only
4: Any number of processes
Ans:3
2 Making a change to the conceptual schema of a database but not affecting the existing external schemas is an example of
Physical data independence
Logical data independence
Functional dependency
Concurrency control
Ans: 2
3 Within a table, each primary key value __.
is a minimal superkey
is always the first field in each table
must be numeric
must be unique
ans:4
4 An entity type is
defined when the database is actually constructed
a specific type such as an integer, text, date, logical etc
a coherent set of similar objects that we want to store data on (e.g. STUDENT, COURSE, CAR)
defined by the database designer
ans: 3
5 Which of the following is INCORRECT statement concerning the database design process?
During requirements collection and analysis phase, one can gather the data requirements of database users.
By referring to a high level data model, it is possible to understand the data requirements of the users, entity types, relationships and constraints.
Transformation of the high level data model into the implementation data model is called logical design or data model mapping.
During the logical design phase of internal storage structures, access paths and file organization for the database files are specified.
ans: 2
6 Which of the following is correct regarding Dataflow diagram?
Single DFD is required to represent a system
Created at increasing levels of detail
The dataflow must be bidirectional
Used to represent the relationships among the external entities
ans: 4
7 Each table must have a __ key.
primary
secondary
logical
foreign
ans: 1
8 An instance is
a particular occurance of an entity
a special type of relation
an attribute of an entity
any particular entity
ans: 3
9 A table can be logically connected to another table by defining a __.
hyperlink
common attribute
primary key
superkey
ans: 2
10 Which of the following is NOT a component of a DFD?
Dataflow
Datastore
External entities
Relationship between external entities
ans: 4
