WorksheetsDatabase Concepts Quiz
Total questions: 75
Worksheet time: 38mins
In an E-R diagram that uses Chen Notation attributes are represented by
rectangle.
square.
ellipse.
triangle.
A logical schema,
is a model usually a diagram with data structures expressed which are independent of DBMS.
is a standard way of organizing information into accessible parts.
describes how data is actually stored on disk.
both (A) and (C)
Related fields in a database are grouped to form a
data file.
data record.
menu.
bank.
In an E-R diagram the uses Crows Foot Notation an entity set is represent by a
rectangle.
ellipse.
diamond box.
circle.
The property / properties of a database system is / are :
It is an integrated collection of logically related records.
It consolidates separate files into a common pool of data records.
Data stored in a database is independent of the application programs using it.
All of the above.
The DBMS language component which can be embedded in a program is
The data definition language (DDL).
The data manipulation language (DML).
The database administrator (DBA).
A query language.
The statement in SQL which allows to change the definition of a table is
Alter.
Update.
Create.
Select.
The Chen Notation ER model uses this symbol to represent weak entity set?
Dotted rectangle.
Diamond
Doubly outlined rectangle
None of these
Which of the following operation is used if we are interested in only certain columns of a table?
PROJECTION
SELECTION
UNION
JOIN
The RDBMS terminology for a row is
tuple.
relation.
attribute.
degree.
The entity integrity rule requires that ________.
all primary key entries are unique
a part of the key may be null
foreign key values do not reference primary key values
duplicate object values are allowed
A relational operator that allows for the combination of information from two or more tables is known as the ____ operator.
SELECT
PROJECT
JOIN
DIFFERENCE
A primary key that consists of more than one field is called a ____ key.
composite
secondary
group
foreign
A relational operator that yields all rows in one table that are not found in the other table is the ____ operator.
UNION
INTERSECT
DIFFERENCE
PRODUCT
An ad hoc query is a ____.
pre-scheduled question
spur-of-the-moment question
pre-planned question
question that will not return any results
Where does the DBMS store the definitions of data elements and their relationships?
Data file
Index
Data dictionary
Data map
A raw fact, such as an invoice date, is known as ____.
information
a record
a relationship
data
Another name for a production database is a ____ database.
development
warehousing
transactional
data-mining
A DBMS performs several important functions that guarantee the integrity and consistency of the data in the database. Which of the following is NOT one of those functions?
Data integrity management
Data storage management
Data reports
Security management
Which of the following is a benefit of using a DBMS?
They provide full security to data using private/public key encryption
They create automatic queries
They help create an environment for centralized control
They provide seamless Internet access to database data
Software that defines a database, stores the data, supports a query language, produces reports and creates data entry screens is a:
data dictionary
database management system (DBMS)
decision support system
relational database
Which of the following items is not the advantage of a DBMS?
Improved ability to enforce standards
Improved data consistency
Local control over the data
Minimal data redundancy
The property (or set of properties) that uniquely defines each row in a table is called the:
identifier
index
primary key
symmetric key
The database design that consists of multiple tables that are linked together through matching data stored in each table is called a:
Hierarchical database
Network database
Object oriented database
Relational database
Which of the following statements is not correct?
All many-to-many relationships must be converted to a set of one-to-many relationships by adding a new entity
Data Normalization is the process of defining the table structure
Individual objects are stored as rows in a table
A primary goal of a database system is to share data with multiple users
In the relational modes, cardinality is termed as:
Number of tuples
Number of attributes
Number of tables
Number of constraints
DML is provided for
Description of the logical structure of the database
Addition of new structures n the database system
Manipulation & processing of database
Definition of physical structure of the database system
The database schema is written in
SQL
DML
DDL
DCL
The view of total database contents is
Conceptual view
Internal view
External view
Physical view
The separation of the data definition from the program is known as:
data dictionary
data independence
data integrity
referential integrity
The statement in SQL which changes the definition of a table
Alter
Update
Create
Select
Which of the following is a legal expression in SQL?
SELECT NULL FROM EMPLOYEE;
SELECT NAME FROM EMPLOYEE;
SELECT NAME FROM EMPLOYEE WHERE SALARY = NULL;
None of the above
Which of the following is a valid SQL type?
CHARACTER
NUMERIC
FLOAT
All of the above
NULL is
The same as 0 for an integer
The same as blank for a character
Both A and B
Not a value
The DROP TABLE statement:
Deletes the table structure only
Deletes the table structure along with the table data
Works whether or not referential integrity constraints would be violated
Is not an SQL Statement
When using the SQL INSERT statement:
Rows can be modified according to criteria only
Rows cannot be copied in mass from one table to another only
Rows can be inserted into a table only one at a time
Rows can either be inserted into a table one at a time or in groups
Normalization _______________ data duplication
Eliminates
Reduces
Increases
Maximizes
Which of the following symbols is NOT used in a Chen Notation ERD?
Rectangle
Oval
Diamond
Circle
Tables in second normal form (2NF):
Eliminate all hidden dependencies
Eliminate the possibility of a insertion anomalies
Have a composite key
Have all non key fields depend on the whole primary key
A functional dependency is a relationship between or among:
Tables
Rows
Relations
Attributes
While inserting new rows in a table you must list values in the default order of the columns.
True
False
Which of the following is true about removing rows from a table?
You remove existing rows from a table using the DELETE statement
No rows are deleted if you omit the WHERE clause.
You cannot delete rows based on values from another table.
All of the above.
Which operator performs pattern matching?
BETWEEN operator
LIKE operator
EXISTS operator
None of these
What operator tests column for the absence of data?
EXISTS operator
NOT operator
IS NULL operator
None of these
Find all the cities whose humidity is 89
SELECT city WHERE humidity = 89
SELECT city FROM weather WHERE humidity = 89
SELECT humidity = 89 FROM weather
SELECT city FROM weather
What is the meaning of LIKE ‘%0%0%’
Feature begins with two 0’s
Feature ends with two 0’s
Feature has more than two 0’s
Feature has two 0’s in it, at any position
Third normal form is based on the concept of ___________
Closure Dependency
Transitive Dependency
Normal Dependency
Functional Dependency
A function that has no partial functional dependencies is in __________ form
3NF
2NF
4NF
BCNF
The ___________ operation allows the combining of two relations by merging pairs of tuples, one from each relation, into a single tuple
Select
Join
Union
Intersection
An attribute in a relation is a foreign key if the ____________ key from one relation is used as an attribute in that relation
Candidate
Primary
Super
Sub
All of the following are features of a flat file database except
All records are stored in one place
Easy to setup
Easy to understand
Unique records
All of the following meets database objectives except
to control redundancy
to standardize data storage
to prevent sharing of data
to maintain data integrity
Which of the following is NOT an expectation we have for a database management system, whether it is relational or not
More complicated handling of requests for information
backup and recovery
efficient storage handling
concurrency
Which of the following is NOT a type of schema corresponding to the three levels in the ANSI-SPARC architecture
Internal
Conceptual
Physical
External
Physical data independence is
The ability to modify the conceptual schema without having alteration in external schema or application programs
The ability to modify the physical schema without causing the conceptual schema application programs to be rewritten
none of these
all of these
Which of the following is NOT true of relational database management systems
Tables are organized into columns
One or more columns uniquely identify a row within the table
Stores data in flat files
An index provides a quick way to look up data
Which of the following is NOT a tool that is available with a complete database management system
Presentation
Report writer
Graphics
Ad-hoc query
Which of the following is NOT true about an Entity Relationship Diagram (ERD)
It shows how the database is physically represented on the computer system
It is based on an abstract, conceptual representation of data called an entity relationship model (ERM)
It consists of a collection of entity types and relationships
It includes attributes for each entity, and multiplicity and participation for each relationship
Which of the following is NOT an acronym of sub languages of SQL
DQL
DHL
DDL
DML
The goal of third normal form (3NF) is to
Eliminate repeating groups
Make non-key attributes fully dependent on the primary key
Remove transitive dependencies
All of these
In which Normal Form should you eliminate repeating groups?
First Normal Form (1NF)
Second Normal Form (2NF)
Third Normal Form (3NF)
None of these
The Boyce-Codd Normal Form is another name for?
First Normal Form (1NF)
Second Normal Form (2NF)
Third Normal Form (3NF)
None of these
When all non-key attributes are fully functionally dependent on the primary key, a table is in
First Normal Form (1NF)
Second Normal Form (2NF)
Third Normal Form (3NF)
None of these
A candidate key that will most commonly be used to uniquely identify a single entity instance is said to be a
Candidate key
Primary key
Concatenated key
Alternate key
A natural business association that exists between one or more entities is a
Relationship
An associative entity
Cardinality
Domain
An atomic transaction is a set of SQL statements where
All succeed
All fail
All succeed or fail
None succeed of fail
The SQL operator that is used where an exact match is not necessary is
%
LIKE
BETWEEN
ANY
A value that is not available or not known is a
Zero value
Unknown value
Missing value
NULL value
To check for a value outside of a range, you can use
NOT RANGE operator
NOT LIKE operator
NOT BETWEEN operator
None of these
The OR operator combines two relational expressions where only one must be true to provide a true result
True
False
The AND operator combines two relational expressions where only one must be true to provide a true result
True
False
The SQL statement ‘Select mod (10,4) from dual’ will display 2 as the result
True
False
The SQL statement ‘select round (1047.785,2) from dual’ will display 1047.78
True
False
‘%abc’ matches strings beginning with ‘abc’
True
False
The HAVING is similar to WHERE, but it can operate on the GROUP BY aggregate functions, whereas WHERE operates only on columns
True
False
