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Introduction and importance of ms excel - class-XII

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A relation is given an identity by its ___and description by its ____.

  1. schema,name

  2. name ,schema

  3. both of the above

  4. none of the above


Correct Option: B

 In relational data model each row of a table is called as ______________.

  1. attribute

  2. domain

  3. data record

  4. relation


Correct Option: C

In relational data model column header is called as_________.

  1. domain

  2. tuple

  3. relation

  4. None of the above


Correct Option: D

Code is known as ________of account.

  1. category

  2. names

  3. identity

  4. none of the above


Correct Option: C

A column header is called an __________, in relational data model.

  1. Domain

  2. Tuple

  3. Attribute

  4. Relation


Correct Option: C
Explanation:

In relational data model, the table name and column names are used to help in interpreting the meaning of values in each row. All values in a column, which belong to a particular domain, are of same data type. A column header is called an attribute.

In database, the ___________ implies that distinct tables have been logically organised and the purpose is to reduce or eliminate redundancy (or duplicity) and also to facilitate better data access.

  1. Shared property

  2. Integrated property

  3. Intellectual property

  4. Both B and C


Correct Option: B
Explanation:

Database has two important properties (or characteristics): one is integrated and second is shared. Integrated property implies that distinct data tables have been logically organised. The purpose is to reduce or eliminate redundancy (or duplicity) and also to facilitate better data access.

The ________ represents the database as collection of relations, which resembles a table of values (or data table).

  1. Relational data model

  2. ER model

  3. Data model

  4. Both A and B


Correct Option: A
Explanation:

relational database is a type of database that stores and provides access to data points that are related to one another. Relational databases are based on the relational model, an intuitive, straightforward way of representing data in tables.

A row is called a _________, in relational data model.

  1. Domain

  2. Tuple

  3. Attribute

  4. Relation


Correct Option: B
Explanation:

The relational data model represents a table of values (or data table). Each row of the table, therefore, represents a collection of related data values and hence typically corresponds to real world entity or relationship. Formally, a row is called a tuple.

In database, __________ means that all those who are authorised to use data/information have access to relevant data.

  1. Shared property

  2. Integrated property

  3. Intellectual property

  4. Both A and B


Correct Option: A
Explanation:

Database has two important properties (or characteristics): one is integrated and second is shared. The shared property means that all those who are authorised to use data/information have access to relevant data.

__________ refers to data that have been processed and organised in a form, which is suitable for decision-making.

  1. Data

  2. Database

  3. Information

  4. Reality


Correct Option: C
Explanation:

Information refers to data that have been processed and organised in a form, which is suitable for decision-making, The raw data processed in accordance with decision usefulness of a decision-maker becomes information.

Among several representational models, __________ is the most popular and widely used in actual practice.

  1. ER Model

  2. Relational Data Model

  3. Data Model

  4. Both ER Model and Relational Data Model


Correct Option: B
Explanation:

Among several representational models, Relational Data Model (RDM) is the most popular and widely used in actual practice. It represents the database as collection of relations, which resembles a table of values (or data table).

__________ is defined as a set of programs, which are designed and developed for a community of users and not for any particular application with respect to a particular user.

  1. Data-purpose software

  2. General-purpose software

  3. General-purpose hardware

  4. Data software


Correct Option: B
Explanation:

Database management system (DBMS) may be defined as a general-purpose software system that facilitates the processes of defining, constructing and manipulating (or processing) databases for various applications, General-purpose software is defined as a set of programs, which are designed and developed for a community of users and not for any particular application with respect to a particular user.

The data type describing the types of values (such as text value, numeric values, data values, currency value, etc.) that can appear in each column is called a ________, which is a set of indivisible values.

  1. Tuple

  2. Domain

  3. Attriibute

  4. Row


Correct Option: B
Explanation:

The data type describing the types of values (such as text value, numeric values, data values, currency value, etc.) that can appear in each column is called a domain. A domain is a set of indivisible values.

When a relation has more than one attribute with unique values, each such attribute is called:

  1. Multi-valued

  2. Full functional

  3. Half functional

  4. None of the above


Correct Option: B
Explanation:

An attribute is fully functional dependent on another attribute, if it is Functionally Dependent on that attribute and not on any of its proper subset. For example, an attribute Q is fully functional dependent on another attribute P, if it is Functionally Dependent on P and not on any of the proper subset of P.

The four constraints that can be specified on relational databases are _____________________.

  1. Domain constraints, Key constraints, Entity integrity constraints and Referential integrity constraints.

  2. Key constraints, Database constraints, Normalisation constraints and Referential integrity constraints.

  3. Domain constraints, Database constraints, Normalisation constraints and Entity integrity constraints.

  4. None of these.


Correct Option: A
Explanation:

There are four different constraints, which can be specified on relational databases. They are domain constraints; key constraints; entity integrity constraints and referential integrity constraints.

A __________ is a set of tuples wherein each tuple is an ordered list of values corresponding to attributes of relation.

  1. Data

  2. Relation

  3. Database

  4. Attribute


Correct Option: B
Explanation:

A relation represents an entity type. A relation (or relation state) is a set of tuples wherein each tuple is an ordered list of values corresponding to attributes of relation.

Each row of a table is called a _________, in relational data model.

  1. Data record

  2. Data table

  3. Data system

  4. Data process


Correct Option: A
Explanation:

The relational data model represents the database as collection of relations, which resembles a table of values (or data table). The table name and column names are used to help in interpreting the meaning of values in each row. Each row of a table is called a data record.

Each simple attribute of an entity type is associated with a value set called _____ of values.

  1. Liveware

  2. Timeware

  3. Entityware

  4. None of the Above


Correct Option: B
Explanation:

Each simple attribute of an entity type is associated with a value set called timeware of values.

A __________ is a set of relation schemas and a set of integrity constraints.

  1. Relational database

  2. Relational database schema

  3. Relational schema

  4. Database schema


Correct Option: B
Explanation:

A relational database schema is a set of relation schemas and a set of integrity constraints. A relational database state is a set of relation state such that every relational database state satisfies the integrity constraints specified on relational database schema.

Entity integrity constraint states that no ______ key value can be null because it is used to identify individual tuple in a relation.

  1. Secondary

  2. Primary

  3. Partial

  4. Particular


Correct Option: B
Explanation:

Entity integrity constraint is one of the constraints on relational database. It states that no primary key value can be null because it is used to identify individual tuple in a relation. Null value implies that we cannot identify such tuples or identify these as alike. A failure to distinguish them means they are duplicates.

The ______ for binary relationship specifies the number of relationship instance that an entity can participate in. 

  1. Timeware based

  2. Computer based

  3. Liveware based

  4. Selection based


Correct Option: B
Explanation:

Cardinality ratios (computer based) for binary relationship specifies the number of relationship instance that an entity can participate in.

The integrity constraints, specified on ________, must hold in every database state of that schema.

  1. Database

  2. Database relation

  3. Database schema

  4. Database system


Correct Option: C
Explanation:

It is a merit for special consideration. The integrity constraints, specified on database schema, must hold in every database state of that schema.

A special value called ______ is used to represent unknown or not applicable values of attributes in a tuple.

  1. Composite

  2. Multi-valued

  3. Null

  4. Both B and C


Correct Option: C
Explanation:

Each value in a tuple is an indivisible value to imply that it is not divisible into components within the framework of the basic relational model. This implies that composite and multi-valued attributes are not allowed. A special value called Null is used to represent unknown or not applicable values of attributes in a tuple.

While ______ and ________ constraints are specified on individual relation, the _______ constraint is specified between two or more relations.

  1. Key, Entity, Referential Integrity

  2. Entity, Candidate, Referential Integrity

  3. Key, Attribute, Referential Integrity

  4. Candidate, Referential Integrity, Attribute


Correct Option: A
Explanation:

While key and entity constraints are specified on individual relation, the referential integrity constraint is specified between two or more relations. This constraint is specified to maintain consistency among the tuples in such relations.

Every relation that has at least one key by default, which is the combination of all its attributes is called _________ by default, which specifies  uniqueness constraint.

  1. Financial key

  2. Super-key

  3. Attribute key

  4. Candidate key


Correct Option: B
Explanation:

Each data record, which corresponds to a tuple of a relation, in a table must be distinct. Every relation has at least one key by default, which is the combination of all its attributes. This key is called super-key by default.

____________ is defined as that part of super-key from which any attribute cannot be removed without sacrificing the uniqueness constraint.

  1. Super key

  2. Minimal super-key

  3. Candidate key

  4. Attribute key


Correct Option: B
Explanation:

Minimal super-key (also called Key) is defined as that part of super-key from which any attribute cannot be removed without sacrificing the uniqueness constraint.

The minimal super-key is also called ______.

  1. Super key

  2. Key

  3. Candidate key

  4. Both A and B


Correct Option: B
Explanation:

Minimal super-key is also called as Key. It is defined as that part of super-key from which any attribute cannot be removed without sacrificing the uniqueness constraint.

___________ operation is carried out to remove a tuple from a relation.

  1. Modify

  2. Delete

  3. Update

  4. Insert


Correct Option: B
Explanation:

There are three basic types of updates: insert, delete and modify. Delete operation is carried out to remove a tuple from a relation. A particular data record from a table can be removed by performing such a operation. The delete operation can violate only referential integrity, if tuple being removed is referenced by foreign key from tuples in the database.

_______ operation on Relational Data Model does not cause violation any integrity constraints.

  1. Retrieval

  2. Updates

  3. Data processing

  4. None of the above


Correct Option: A
Explanation:

There are two categories of operations on relational model: updates and retrieval operation on Relational Data Model does not cause violation any integrity constraints. 

Which of the following are the constraints of database schemas?
a. Domain constraints, Key constraints, Entity integrity constraints, Referential integrity constraints
b. Domain constraints, Data constraints, Entity integrity constraints, Referential integrity constraints

  1. Only "a"

  2. Only "b"

  3. Both "a" and "b"

  4. None of the above


Correct Option: A
Explanation:

A relational database schema is a set of relation schemas and a set of integrity constraints. There are four different constraints, which can be specified on relational database. These are: domain constraints, key constraints, entity integrity constraints, referential integrity constraints. 

Which of the following statements are correct for Relational Data Model (RDM):
a. Relational Data Model (RDM) is the most popular and widely used in actual practice.
b. Relational data model represents the database as collection of relations, which resembles  a table of values. 

  1. Only "a" is correct.

  2. Only "b" is correct.

  3. Both "a" and "b" are correct.

  4. None of the above is correct.


Correct Option: C
Explanation:

The relational data model represents the database as collection of relations, which resembles a table of values (or data table). Each row of the table, therefore, represents a collection of related data values and hence typically corresponds to real world entity or relationship. Among several representational models, Relational Data Model (RDM) is the most popular and widely used in actual practice. 

The value of each attribute of a relation must be an indivisible value and drawn out of possible values associated with its ________. 

  1. Entity

  2. Key

  3. Domain

  4. Referential


Correct Option: C
Explanation:

The domain is one of the constraints, which can be specified on relational databases. The value of each attribute of a relational must be an indivisible value and drawn out of possible values associated with its domain. The value of an attributed, therefore, must conform to the data type associated with the domain.

A ________ state is a set of relation states such that every relational database state satisfies the integrity constraints specified on relational database schema.

  1. Accounting database

  2. Relational database

  3. data management

  4. Database technology


Correct Option: B
Explanation:

A relational database schema is a set of relation schemas and a set of integrity constraints. A relational database is a set of relation states such that every relational database state satisfies the integrity constraints specified on relational database schema.

The ___________ model represents the database as collection of relations, which resembles a table of values (or data table).

  1. relational data

  2. entity integrity

  3. referential integrity

  4. entity relationship


Correct Option: A

While key and entity constraints are specified on individual relation, the referential integrity constraints is specified between _________ relations. 

  1. one or more

  2. two or more

  3. one or two

  4. none of the above


Correct Option: B
Explanation:

While key and entity constraints are specified on individual relation, the referential integrity constraints is specified between two or more relations. This constraint is specified to maintain consistency among the tuples of such relations.

The two categories of operations on relational model are ______ and ______.

  1. Insert, Delete

  2. Updates, Retrieval

  3. Updates, Delete

  4. Retrieval, Insert


Correct Option: B
Explanation:

A relational database schema is a set relation schemas and integrity constraints. It is a set of relation states such that relational database state satisfies the integrity constraints specified on relational database schema. There are two categories of operations on relational model: updates and retrieval. Update operation are of three basic types i.e. insert, delete and modify. Retrieval operation on relational data model does not cause violation of any integrity constraints.

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