______contains information that defines valid values that are stored in a column or data type.
Default
Index
Rule
View
Correct Answer :
B. Index
Related Questions
Relational Algebra does not have
Selection operator.
Projection operator.
Aggregation operators.
Division operator.
______is a preferred method for enforcing data integrity
Constraints
Triggers
Stored procedure
Cursors
Between DRAM and magnetic disk storage another form of memory, called ______ memory is becoming common because it is non volatile.
RAM
Flash
Hard Disk
Secondary
DBMS is a collection of _____ that enables user to create and maintain a database.
Keys
Program
Translators
Language Activity
Drop Table cannot be used to drop a table referenced by a ______ constraint.
Primary Key
Local Key
Foreign Key
Composite Key
A data type or format is specified for each _________
Relation
Tuple
Database
Domain
Checkpoints are a part of
Recovery measures.
Security measures.
Concurrency measures.
uthorization measures.
The default level of consistency in SQL is
repeatable read
read committed
read uncommitted
serializable
For using a specific database …………… command is used.
use database
database name use
Both A & B
None of them
If two relations R and S are joined, then the non matching tuples of both R and S are ignored in
left outer join
right outer join
full outer join
inner join
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
A _____ is used to define overall design of the database
code
data definition language
application program
schema
According to the levels of abstraction, the schema at the intermediate level is called
Logical schema.
Physical schema.
Subschema.
None of the above.
An advantage of views is
Data security
Derived columns
Hiding of complex queries
All of the above
_____ database is used to provide statistical information or summaries of values based on various criteria.
Statistical
Mathematical
Normalized
Un normalized
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.
Which of the following is not a characteristic of a relational database model?
Table
Tree like structure
Complex logical relationship
Records
A table can have only one
Secondary key
Alternate key
Unique key
Primary key
_____ First proposed the process of normalization.
Edgar. W
Edward Stephen
Edgar F. Codd
Edward Codd
Whenever two independent one-to-many relationships are mixed in the same relation, a __________ arises.
Functional dependency
Multi-valued dependency
Transitive dependency
Partial dependency
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
When an E-R diagram is mapped to tables, the representation is redundant for
weak entity sets
weak relationship sets
strong entity sets
strong relationship sets
If an entity can belong to only one lower level entity then the constraint is
disjoint
partial
overlapping
single
It is an abstraction through which relationships are treated as higher level entities
Generalization.
Specialization.
Aggregation.
Inheritance.
The normalization was first proposed by .
Code
Codd
Boyce Codd
Boyce
Which of the following is not a consequence of concurrent operations?
Lost update problem.
Update anomaly.
Unrepeatable read.
Dirty read.
Maximum height of a B+ tree of order m with n key values is
Logm(n)
(m+n)/2
Logm/2(m+n)
None of these
The middleware databases in which the business rules act are applicable to _______ tier architectures
Single
Three
Two
None
In an E-R, Y is the dominant entity and X is a subordinate entity. Then which of the following is incorrect :
Operationally, if Y is deleted, so is X
existence is dependent on Y.
Operationally, if X is deleted, so is Y.
Operationally, if X is deleted, & remains the same.
SQL server stores index information in the _____system table
system indexes
syst indexes
sys indexes
sysind