What is data integrity?
It is the data contained in database that is non redundant.
It is the data contained in database that is accurate and consistent.
It is the data contained in database that is secured.
It is the data contained in database that is shared.
Correct Answer :
B. It is the data contained in database that is accurate and consistent.
(Data integrity means that the data must be valid according to the given constraints. Therefore, the data is accurate and consistent.)
Related Questions
In an ER diagram the ___shape specifies the Attibute and a ____ shape specifies the primary key attribute.
Oval; An oval with an underlined attribute
Circle; A circle with bolded attribute inside it
Diamond; A bolded attribute
Square; An attribute within the square
The fact that information in the data warehouse changes far less often and may be regarded as non-real-time with periodic updating; This implies that data warehouses are _______
Volatile
Non - Volatile
Logical
Physical
If an entity can belong to only one lower level entity then the constraint is
disjoint
partial
overlapping
single
Data items grouped together for storage purposes are called a
record
string
title
list
Which two files are used during operation of the DBMS?
Query languages and utilities
DML and query language
Data dictionary and transaction log
Data dictionary and query language
In E-R Diagram total participation is represented by
Double lines
Single line
Dashed lines
Triangle
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
Wait-for graph is used for
detecting view serializability.
detecting conflict serializability.
deadlock prevention
deadlock detection
A transaction is in state after the final statement has been executed.
partially committed
active
committed
none of the above
A top-to-bottom relationship among the items in a database is established by a
Hierarchical schema
Network schema
Relational Schema
All of the above
Which of the following aggregate functions does not ignore nulls in its results?.
COUNT .
COUNT (*)
MAX
MIN
The ______ indexes are forced to store only record IDs in the data structure and require at least one additional I/O Operation to retrieve the actual record.
Clustered
Hashed
Un-clustered
Collision
A table can have only one
Secondary key
Alternate key
Unique key
Primary key
The language that requires a user to specify the data to be retrieved without specifying exactly how to get it is
Procedural DML.
Non-Procedural DML.
Procedural DDL.
Non-Procedural DDL.
Which of the following is not a characteristic of a relational database model?
Table
Tree like structure
Complex logical relationship
Records
In multiple granularity of locks SIX lock is compatible with
IX
IS
S
SIX
Union operator is a :
Unary Operator
Ternary Operator
Binary Operator
Not an operator
According to the levels of abstraction, the schema at the intermediate level is called
Logical schema.
Physical schema.
Subschema.
None of the above.
_____ command can be used to modify a column in a table
alter
update
set
create
The clause alter table in SQL can be used to
add an attribute
delete an attribute
alter the default values of an attribute
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
______ keyword is used to find the number of values in a column.
TOTAL
ADD
COUNT
SUM
Relational Algebra does not have
Selection operator.
Projection operator.
Aggregation operators.
Division operator.
The default level of consistency in SQL is
repeatable read
read committed
read uncommitted
serializable
Isolation of the transactions is ensured by
Transaction management
Application programmer
Concurrency control
Recovery management
Processed data is called _____
Raw data
Source
Information
Useful data
In a relational schema, each tuple is divided into fields called
Relations
Queries
Domains
All of the above
Which of the following is true for network structure?
It is a physical representation of the data.
It allows many to many relationship.
It is conceptually simple.
It will be the dominant database of the future.
______is a special type of integrity constraint that relates two relations & maintains consistency across the relations.
Domain Integrity Constraints
Referential Integrity Constraints
Domain Constraints
Entity Integrity Constraints
The clause in SQL that specifies that the query result should be sorted in ascending or descending order based on the values of one or more columns is
View
Order by
Group by
Having