The concept of mapping of ______ entity types is the concept in which the for each strong entity type E in the ER schema, create a relation R that includes all the simple attributes of E.
Regular
Irregular
None
Weak
Correct Answer :
A. Regular
Related Questions
Tree structures are used to store data in
Network model.
Relational model.
Hierarchical model.
File based system.
What is a disjoint less constraint?
It requires that an entity belongs to no more than one level entity set.
The same entity may belong to more than one level.
The database must contain an unmatched foreign key value.
An entity can be joined with another entity in the same level entity set.
Employees in a company are each assigned their own office, i.e. for each employee there exists a unique office and for each office there exists a unique employee; This statement is an example of ____ type of relation.
1:1
1: Many
Many: One
Many : Many
Drop Table cannot be used to drop a table referenced by a ______ constraint.
Primary Key
Local Key
Foreign Key
Composite Key
The division operator divides a dividend A of degree m+n by a divisor relation B of degree n and produces a result of degree
m - 1
m + 1
m * m
m
An advantage of the database management approach is
data redundancy increases
data is dependent on programs
data is integrated and can be accessed by multiple programs
none of the above
The transactions like adding an employee, enrolling a student in a course are examples of _______
Logical
Physical
None
Theoretical
A weak entity has an ______ dependency on its owner entity, which can be used for both ON UPDATE and ON DELETE.
Direct
Indirect
Existence
No
Data independence means
data is defined separately and not included in programs.
programs are not dependent on the physical attributes of data
programs are not dependent on the logical attributes of data
both B and C
An advantage of views is
Data security
Derived columns
Hiding of complex queries
All of the above
The relational model is based on the concept that data is organized and stored in two-dimensional tables called ______
Fields
Records
Relations
Keys
What will be the number of columns and rows respectively obtained for the operation, A- B, if A B are Base union compatible and all the rows of a are common to B? Assume A has 4 columns and 10 rows; and B has 4 columns and 15 rows
4,0
0,0
4,5
8,5
A data type or format is specified for each _________
Relation
Tuple
Database
Domain
The normalization was first proposed by .
Code
Codd
Boyce Codd
Boyce
_____ database is used to provide statistical information or summaries of values based on various criteria.
Statistical
Mathematical
Normalized
Un normalized
DBMS helps achieve
Centralized control of data
Data independence
Both A and B
Neither A nor B
The _____ category includes storage media that can be operated on directly by the computers central processing unit.
Primary storage
Secondary Storage
All
Tertiary Storage
The concept of mapping of ______ entity types is the concept in which the for each strong entity type E in the ER schema, create a relation R that includes all the simple attributes of E.
Regular
Irregular
None
Weak
The ______ language consists of SQL statements for operating on the data (insert, Modify, Delete) in tables that already exist.
Data Manipulation
Data Definition
Data Control
None
______defines the structure of a relation which consists of a fixed set of attribute-domain pairs.
Instance
Program
Schema
Super Key
______contains information that defines valid values that are stored in a column or data type.
Default
Index
Rule
View
In 2NF
No functional dependencies (FDs) exist.
No multivalued dependencies (MVDs) exist.
No partial FDs exist.
No partial MVDs exist.
The ____ operator joins two or more conditions and displays rows only if that rows data satisfies all conditions specified.
OR
AND
NOT
ALL
Assume transaction A holds a shared lock R. If transaction B also requests for a shared lock on R.
It will result in a deadlock situation.
It will immediately be rejected.
It will immediately be granted.
It will be granted as soon as it is released by A .
Which of the following is not a recovery technique?
Deferred update
Immediate update
Two-phase commit
Shadow paging
Given the following relation S(SNO,SNAME,CITY) write a query to update the value of CITY to KANPUR for the supplier S1.
UPDATE S CITY = KANPUR WHERE SNO=S1
UPDATE S SET CITY = KANPUR FOR SNO=S1
UPDATE S SET CITY = KANPUR WHERE SNO=S1
UPDATE S RENAME CITY = KANPUR WHERE SNO=S1
In an E-R diagram double lines indicate
Total participation.
Multiple participation.
Cardinality N.
None of the above.
Cascading rollback is avoided in all protocol except
strict two-phase locking protocol.
tree locking protocol
two-phase locking protocol
validation based protocol.
In E-R Diagram total participation is represented by
Double lines
Single line
Dashed lines
Triangle
If the closure of an attribute set is the entire relation then the attribute set is a
superkey
candidate key
primary key
not a key