Top 1000+ Database Subject Mcqs Pdf Download Set No 04
151.Select the correct statement among the following on proper naming of schema constructs
- Entity type name applies to all the entities belonging to that entity type and therefore a plural name is selected for entity type.
- In the narrative description of the database requirements, verbs tend to indicate the names of
- relationship types.
- The nouns arising from a database requirement description can be considered as names of attributes.
- Additional nouns which are appearing in the narrative description of the database
- requirements represent the weak entity type names.
152.Identify the constraint that limits the values that can be placed in a column.
- Not null
- Check
- Foreign Key
- Unique
153.which has conceptual existence like a course in a degree program as an entity?
- Age can be considered as a single value attribute of a person.
- An entity type describes the schema or intension for a set of entities
- share the same structure.
154. If W, X, Y and Z are attributes of a relation, which of the following inference rules for functional Which is correct? Select correct option
- One process at least
- Two processes at least
- One process only
- Any number of processes
156.A ______ is used to maintain a connection between the users of the database system. Select correct option
- Mail server
- File Server
- Client-server
- None of the given.
157.Which of the following is NOT a component of a DFD?
- Dataflow
- Data store
- External entities
- Relationship between external entities
158.Which of the following is correct regarding Dataflow diagram?
- Single DFD is required to represent a system
- The dataflow must be bidirectional
- Created at increasing levels
- Used to represent the relationships among the external entities
159.Which of the following is CORRECT about database management system’s languages?
- Data definition languages are used to specify the conceptual schema only. Data manipulation languages are used to create the databases.
- Data manipulation languages are used for retrieval, insertion, deletion and modification of data.
- Data definition languages are only used to update data in the DBMS.
160.Which of the following concepts is applicable with respect to 3NF?
- Full functional dependency
- Any kind of dependency
- Transitive dependency
- Partial functional dependency
161.Consider two sets A and B. A contains 3 elements and B contains 4. How many elements do their Cartesian product contains?
- 12
- 9
- 16
- 7
162.Consider two sets A and B. A contains 2 elements and B contains 3. How many elements do their Cartesian product contains?
- 6
- 9
- 4.5
163.Which of the following is not true about relational tables?
- Column values are of the same kind.
- Each row is unique.
- Each column must have a unique name.
- The sequence of rows is significant.
164.Identify the operation which is NOT one of the parts of the five basic set operations in relational algebra?
- Join
- Union
- Cartesian Product
- Set Difference
165.Consider the following statements.
- An entity integrity constraint states that no primary key value can be null.
- A referential integrity constraint is specified between two relations.
- C.A foreign key cannot be used to refer
Identify which of the above statements is/are correct.
- Only A
- Only B
- Only B and C
- Only A and B
166.If K is a foreign key in relation R1, then every tuple of R1 has a distinct value for K.
- K cannot have a null value for tuples in R1.
- K is a key for some other relation.
- K is a primary key for R1.
167.Identify the operation which is NOT one of the parts of the five basic set operations in relational algebra?
- Ź Join
- Ź Union
- Ź Cartesian Product
- Ź Set Difference
168.An entity integrity constraint states that no primary key value can be null.
A referential integrity constraint is specified between two relations.
A foreign key cannot be used to refer to its own relation.
Identify which of the above statements is/are correct.
- Only A
- Only B
- Only B and C
- Only A and B
169.Name three kind of basic binary operation on relational algebra
- Union
- Set operation
- Cartesian product
170. Data type
- Data type is defined as a set of values along with the operations
- Some common data types are Integer, Float, Variable char, Char,
- all
171.What is the importance of minimum cardinality in relation while designing the database.
- Minimum Cardinality
- T/F
- T
172.Shortly describe Procedural DML and Non procedural DML
- Procedural Languages
- Non -Procedural Languages
- Structured query language (SQL)
- all
173. Each table must have a ____ key
Select correct option
- primary
- secondary
- logical
- foreign
174. 1 In a three-level DBMS architecture, the ______ level interacts directly with the users .
Select correct option
- external
- conceptual
- internal
- physical
175 .A collection of concepts that can be used to describe the structure of a database Select correct option
- Database
- DBMS
- Data model
- Data
176 .Which of the following constraints enforces entity integrity? Select correct option
- PRIMARY KEY
- FOREIGN KEY
- CHECK
- NOT NULL
177.Which feature of database provides conversion from inconsistent state of DB to a consistent state ensuring minimum data loss ?
Select correct option
- User accessible
- Catalog
- Data processing
- Recovery service
178.Which of the following is NOT a component of a DFD? Select correct option
- Dataflow
- Data store
- External entities
- Relationship between external entities
179Data inconsistency leads to a number of problems such as Select correct option ?
- loss of information and incorrect results
- less secure data
- redundant data
- Slow database development
180.User rights information is stored in
Select correct option
- Physical database
- Catalog
- Logical database
- Buffer
181.A table can be logically connected to another table by defining a ____. Select correct option
- hyperlink
- common attribute
- primary key
- super key
182. Which levels are mostly used for Detailed DFD? Select correct option
- Level-0, Level-1
- Level-1, Level-2
- Level-2, Level-3
- Level-3, Level-4
183. Which of the following constraints enforces entity integrity?
Select correct option
- PRIMARY KEY
- FOREIGN KEY
- CHECK
- NOT NULL
184.The most widely used conceptual model is the ____ model. Select correct option
- implementation
- ER
- Object Oriented internal
- all
185.201PK?
- A primary key is an attribute
- (or set of attributes )
- values
186..particular instance entity.
True
false?
Select correct option
- True
- False
- None of the given
187.Which model operates at the lowest level of abstraction? Select correct option
- conceptual
- internal
- external
- physical
188.Which feature of database provides conversion from inconsistent state of DB to a consistent state ensuring minimum data loss ?
Select correct option
- User accessible catalog
- Data processing
- Recovery service
- Authorization service
189. A description on a particular collection of data using the given data model Select correct option
- Database
- Relation
- Schema
- None
190.A candidate key that does not have a null value and is selected to uniquely identify all other attribute values in any given row is called a ____.
Select correct option
- super key
- candidate key
- primary key
- secondary key
191. Data inconsistency leads to a number of problems such as Select correct option
- loss of information and incorrect results
- less secure data
- redundant data
- Slow database development
192.Wich of the following constraints enforces entity integrity? Select correct option
- PRIMARY KEY
- FOREIGN KEY
- CHECK
- NOT NULL
193.Which of the following is a feature of CHECK constraint? Select correct option
- limit the values that can be placed in a column.
- used to enforce referential integrity.
- enforces the uniqueness of the values in a set of columns .
- is a unique identifier for a row within a database table.
194. In “One to Many” cardinality one instance of a relation is mapped with Select correct option many instances of second entity type
- One instance of second entity type
- Primary key of 2 relations
- none of above
195. Binary relationships are those, which are established between Select correct option
- One entity type
- Two entity type
- Three entity type
- Unlimited entities
196.in “many to many relationship” one instance of first entity can be mapped with many instances of second entity Select correct option
true
false
197.Which feature of database provides conversion from inconsistent state of DB to a consistent state ensuring minimum data loss ?
- User accessible catalog Data processing
- Authorization service
- Recovery service
198.Which of the following statements is true about the views? view is always a complete set of all the tables in a database
- View can not be used for retrieving data
- The results of using a view are not permanently stored in the database.
- Rows can not be updated or deleted in the view
- all
199.Which of the following is true about TRUNCATE?
- Can be Rolled back.
- Activates Triggers .
- DML Command.
- Resets
200.Which of the following is the correct way to find out the size of cartesian product incase of CROSS JOIN?
- Number of columns in the first table multiplied by the number of columns in the second table.
- number of columns in the first table multiplied by the number of rows in the second table.
- the number of rows in the first table multiplied by the number of columns in the first table.
- the number of rows in the first table multiplied by the number of rows in the second table.