Plus One Accountancy Chapter Wise Questions and Answers Chapter 11 Computerised Accounting System

Kerala Plus One Accountancy Chapter Wise Questions and Answers Chapter 11 Computerised Accounting System

Plus One Accountancy Structuring Database for Accounting One Mark Questions and Answers

Question 1.
_______are known facts that can be recorded and which have implicit meaning.
Answer:
Data.

Question 2.
Data transformation is called_______.
Answer:
Information

Question 3.
Anything in the real world with independent existence is called______.
Answer:
Entity

Question 4.
______represents the database at collection of tables comprising different volumes.
Answer:
Relational Data Model (RDM)

Question 5.
_______is a collection of concepts used to describe the structure of a database.
Answer:
Data Model

Question 6.
A______does not have key attributes of its own.
Answer:
Weak entity

Question 7.
Each simple attribute of an entity type is associated with a value set called______of values.
Answer:
Time ware

Question 8.
When structure of AIS is based on both human and computer resources, it is called______AIS.
Answer:
Liveware

Question 9.
SQL stands for_______.
Answer:
Structured Query Language

Question 10.
_______is a collection of all entity instances of a particular entity type.
Answer:
Entity Set

Question 11.
Qualification of a person is a______attribute.
Answer:
Multi-valued

Question 12.
Height of a person is______attribute.
Answer:
Single valued

Plus One Accountancy Structuring Database for Accounting Two Mark Questions and Answers

Question 1.
What is Database?
Answer:
Database can be defined as “any organised collection of information. It is a centrally controlled integrated collection of logically organised data.
For example: a data regarding purchase order may be required by accountants, financial manager, and purchase managers. In such a case, interrelated data should be properly organised and stored. Such a collection of interrelated data are called ‘database’.

Question 2.
What do you mean by DBMS?
Answer:
A Database Management system is a software system that manages the creation and use of databse. It is a general purpose software system which helps the users in the process of defining, creating, updating, reading, maintaining and protecting the database. All access to the database is through the database management system. It helps the users to obtain data in a more orderly and logical fashion.

Question 3.
What are the functions of DBMS in a supermarket?
Answer:
With the help of DBMS the present volume of sales is known and this information together with past records and perhaps statistics obtained from market research, forms some of the data needed for sales forecasting which in turn influence stock control. Computers are widely used in everyday cash transactions. Computer help to minimise excess stock and release money for other purpose.

Question 4.
What is meant by Null value? What-are the reasons that lead to their occurrence in database relations?
Answer:
Absence of a data item is represented by a special value called null value. There are three situation which may require the use of null values.

• When a particular attribute doesnot apply to an entity.
• Value of an attribute is unknown, although it exists.
• Unknown because it does not exist.

Question 5.
What do you mean by Multi-valued attribute? How is it different from complex and composite attribute?
Answer:
An attribute with multiple values for an entity is called multivalued attributes. For example the qualifications of a person.
The composite attributes can be divided into smaller sub-parts to represent some more basic attributes with independent meanings. For example – Name of a person that is normally subdivided into First name, Middle name, and Last name is a composite attribute.

The composite and Multi-valued attributes may be grouped into constitute “Complex ones”. The paren-thesis () are used for showing grouping of components of composite attributes. The braces {} are used for showing the multi-valued attributes.

Question 6.
State main categories of data model.
Answer:

1. Relational Data Model
2. Hierarchical model
3. Network model

Question 7.
What is a participation role? State the circumstances under which the use of role names becomes necessary in description of relationship types.
Answer:
Each entity type that participates in a relationship type plays a particular role in the relationship. The role name signifies the role that a participating entity of an entity type plays in each relationship instance.

In PREPARED BY relationship type, EMPLOYEE plays the role of document creator and voucher plays the role of document created. Entity TEACHER and Entity STUDENT are related with a relationship TEACHER – teach – STUDENT. The teaches is a participating role in the entity set TEACHER and STUDENT.

Question 8.
Distinguish between stored and derived attribute.
Answer:
Two or more attributes may be related in such a way that one or more becomes basic while other becomes dependent on that basic attribute.
E.g.:- Date of birth of a person is a stored attribute while age of that person is derived attribute.

Plus One Accountancy Structuring Database for Accounting Three Mark Questions and Answers

Question 1.
What are the functions of DBMS in the following organisations?

1. Insurance
2. Railway
3. Bank
4. Telecom department
5. Payroll department

Answer:

1. Insurance – To enter the data relating to the amounts of insurance premium paid, date of payment, date of maturity, etc. and to retrieve the same.
2. Railway – For reservation of railway tickets.
3. Bank – Money can be deposited in one bank and be withdrawn from another bank.
4. Telecom department – Enter customers details, amount of bill, date of payment, etc.
5. Payroll department – To enter the name of the employee, amount and date of payment and type of employees.

Question 2.
What is meant by Key attributes of an Entity type?
Answer:
Every entity has one of its attributes, which contains unique values for identifying the entity instances is called identifier or key attributes of an entity type.
For example, “RollNo” as attribute of Entity type ‘Student’ has unique values through which a student instance can be identified. Similarly, code is a key attribute of entity type ‘Accounts’ because its data values are required to be unique.

Question 3.
What do you understand by relationship type? How is it different from relationship instance and relationship set?
Answer:
Whenever entities from different entity types are related to one another in a particular manner, they constitute a relationship type. The relationship prepared by between the two entity types vouchers and employees associates each voucher with the employees who prepared it.

Similarly, the relationship authorised by between the two entity types, vouchers and employees associate each voucher with the employee who authorises it.

The degree of a relationship type is the number of participating entity types. A relationship type of de-gree two is called binary and that of degree three is called ternary. AVOUCHER (entity), Authorised by (relationship) and EMPLOYEES (entity) together signify a binary relationship.

ASUPPLIER (entity) SUPPLY (relationship) PARTS (entity) to PROJECT (entity) signify a ternary relationship because three entities, namely supplier, parts, and projects are participating in supply relationship in any transaction.
Relationship sets

• 1: 1 (one to one relationship set)
• 1: M (one to many relationship set)
• M: M (Many to many relationship set)

Question 4.
What do you understand by the concept of weak entity used in data modelling? Explain the relevance of owner entity type, partial key and identifying relationship in the context of such modelling.
Answer:
Weak Entity Types:
Entity Types, which do not have identifier (or key attributes) of their own are, called weak entity types. Such entity types are identified by some of their attribute values. These other entity types are called identifying or owner entity type. Accordingly, the relationship type that relates a weak entity type to its owner is called identifying relationship of the weak entity.

A weak entity type always has a total participation constraint (existence dependency) with respect to its identifying relationship because it cannot be identified without its owner entity, eg. a voucher may be accompanied by a set of support documents such as bills, issued by other parties to the transaction, details of which need to be stored. Such SUPPORT DOCUMENT entity type which is used to keep track of support documents attached to each voucher via 1:N relationship is a weak entity.

This is because they are identified as distinct entities only after determining the particular voucher. A weak entity type normally has a partial key, which is a set to attribute that can uniquely identify weak entities that are related to the same owner entity.

Assuming that two support documents of a voucher do not have the same document Id, the said id can be a good partial key. Otherwise a composite attribute of all the weak entity’s attributes will be the partial key.

Question 5.
Define foreign key. How is this concept useful in relational data model? Illustrate with suitable example.
Answer:
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 typles of such relations.

Accordingly, a tuple in one relation that refers to another relation must refer to an existing tuple in that other relation. In referencing Accounts type, Accounts relation uses its attributes Type, which acts as foreign key to reference the tuples of relation Accounts type through its primary key Catld.

The value of Type cannot be null because of total participation of Accounts in classify relationship.
Say e.g. there are two tables EMP (EMPNO, ENM, SAL, DPTNO (Foreign key)
DEPT (DPTNO (Primary key), DNM, LOC)
The foreign key DPTNO of EMP table takes its value as a reference from DEPT TABLE DPTNO.

Question 6.
What integrity constraints are specified on database scheme? Why each is considered important?
Answer:
While key and entity constraints are specified on invidividual relation, referential integrity is specified between two or more relations. This constraint is specified to maintain consistency among the tuples of such relations.

Accordingly, a tuple in one relation that refers to another relation must refer to an existing tuple in that other relation. In referencing Accounts Type, Accounts relation uses its attribute Type, which acts as foreign key to reference the tuples of relation Accounts Type through its primary key Catld. The value of Type cannot be null because of total participation of Accounts in classify relationship.

For example, there are two tables EMP (EMPNO, ENM, SAL, DPTNO (Foreign Key) DEPT (DPTNO {Primary key}, DNM, LOC). The foreign key DPTNO of EMP table takes its value as a reference from DEPT TABLE DPTNO.

Question 7.
In relational data model, a row is called______, a column header is called on_____and the table as such is called a______.
Answer:

• a row is called a tuple
• a column header is called an attribute
• The table is called a relation.

Plus One Accountancy Structuring Database for Accounting Four Mark Questions and Answers

Question 1.
Explain Entities and Attributes.
Answer:
Entities
Anything in the real world with independent existence is called entity such as an object with physical existence (example – car, person, house) or conceptual existence (example – job, university, account, voucher, a company). In accounting reality, there exist five entities – Accounts, vouchers, employees, accounts type and support documents.

Attributes
Attributes are some properties of interest or characteristics that further describe the entity such as height, weight and date of birth in case of a person and code and name in case of accounts. An entity has a value for each of its attributes, which is the data stored in the database.

In the context of the accounting reality, the following, attributes specific to each entity types have been stated below as:

Question 2.
Discuss the process of designing a Database for Accounting.
Answer:
The process of designing a database for accounting is described below:
1. Reality:
It refers to some aspect of real world situation, for which database is to be designed. In the case of accounting, it is accounting reality that is to be expressed with complete description.

2. ER Design:
This is formal blue print, a pictorial presentation, in which Entity Relations Model concepts are used to represent description of reality.

3. Relational Data Model:
It represents a collection of related data values and hence typically corresponds to real world entity or relationship. It consists of rows and columns.

The table name and column name are used to help in interpreting the meaning of volumes of each rows. Each row of a table is called a data record. All values in a column, which belongs to a particular domain, are of same data type.

4. Normalisation:
This is the process of refining a database design through which the possibility of duplicate or redundant data items is reduced or eliminated.

5. Refinement:
This is the outcome of the process of normalisation. The final database design is arrived at after the process of normalisation is completed. The following chart showing the process of designing a Database for Accounting:

Question 3.
What do you mean by Entity Type? How it is different from entity set?
Answer:
Entity Types and Entity Sets
An entity type is defined as a collection of entities, which share a common definition in terms of their attributes. Each entity type is assigned a name for its subsequent identification. The attributes of entity type are used to describe it in the database. The value of attributes of an entity belonging to entity type are known as “Entity Instance”.

An entity set is a collection of all entity instances of a particular entity type. An entity type is described by a set of attributes called “Schema”. The set of entities pertaining to a particular entity type share the same set of attributes. The collection of entities of a particular entity type is grouped into entity set, called the extension of the entity type.
For example: Entity type: Accounts

Entity set: Collection of entity instances of an entity
Extension or Instances of entity type:

Question 4.
Discuss the basic concepts of Entity-Relationship (ER) Model. Illustrate as to how an ER model is diagrammed.
Answer:
It is a popular conceptual data model, which is mostly used in database-oriented applications. The major elements of ER model are entities, attributes, identifiers and relationships that are used to express a reality for which a database is to be designed.

The model is best depected with the help of ER symbols, the list and description of which is shown in figure below. The formal blue print with a pictorial presentation of ER model is called as ER Diagram. While preparing an ER Diagram, the following symbols are used to represent different types of entities, attributes, identifiers, and relationships.

The elements of ER model that are meant to describe and display the reality are discussed in the context of an accounting reality given below.

Question 5.
Discuss the different types of update operations in relation to the integrity constraints which must be satisfied in a relational database model.
Answer:
The following are the update operations in a relation base model. The three basic types of updates are as given below:
1. insert:
This operation is performed to add a new tuple in a relation, eg. an attempt to add another record of an account with data values corresponding to Code, Name and its Type to Accounts relation shall be made by performing insert operation. The insert operation is capable of violating any of the four constraints.

2. Delete:
This 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 referred by foreign key from other tuples in the database.

3. Modify:
The operation aims at causing a change in the values of some attribute in existing tuples. This is useful in modifying existing values of an accounting record in a data table. Usually, this operation does not cause problems provided the modification is directed on neither primary key or foreign key.

Whenever applied, these operations must enforce integrity constraints specified on relational database schema. Retrieval operation on Relational Data Model does not cause violation of any integrity constraints.

Plus One Accountancy Structuring Database for Accounting Eight Mark Questions and Answers

Question 1.
Discuss the steps you would take to transform an ER Model into various relations of Relational Data Model. Give suitable examples.
Answer:
The rules or guidelines required to design the relational database scheme attempt to provide a step by step procedure that transforms ER design into Relational Data Model design to constitute the desired database.
The following specific steps are required to cause its transformation into relational data model.
1. Create a Relation for Every Strong Entity:
For each strong entity type (which has primary key) in ER schema, a separate relation that includes all the simple attributes of that entity is created.

Either choose bn of the key attributes of such an entity as the primary key for this relation, or choose a set of simple attributes that uniquely identify this entity as the primary key of the relation so created,

eg. employee entity is strong because its finds its primary key in Empld which is one of its unique attribute. Therefore, a separate relation for employee has been created as shown below.

Employee (Empld, Fname, Minit, Lname, Address, PhoneNo, Superld). Similarly, separate relations need be created for the following strong entities whose Primary key attribute have been underlined.

• Accounts (Code, Name, Type)
• Vouchers (VNo, vDate, amount, narration)
• Accounts Type (Catld, Category)

2. Create a separate relation for each weak entity type:
Every weak entity has an owner entity and an identifying relationship through which such weak entity type is identified. For every weak entity type, a separate relation is created by including its attributes. The primary key of this new relation is the combination of its unique attribute(s) for a particular tuple of the owner relation along with primary key attribute of such owner relation.

Furthermore, the primary key of owner entity is included as foriegn key in such a relation key of owner entity and the partial key of weak entity, eg. Support entity, with Vouchers as its owner Entity, does not have a primary key of its own.

It has partial key which is the Sno assigned to each document. Therefore, the Primary key of Vouchers, Vno along with Sno is designed as composite key for support entity and the relation so formed is shown below as
Support (vNo, Sno, dName, sDate)

3. Identify Entity Types Participating in Binary 1: N Relationship Type:
Identify the first relation on n-side of relationship and second on 1-side of such relationship. The primary key of second relation should be included in first relation as its foreign key. eg. An employee can authorize a number of vouchers. It implies that Vouchers entity participates in Auth.

By relationship on n-side while Employees entity participates in same relationship on 1-side. Therefore, the vouchers relation as already formed above in step 1, must also include as foreign key the primary key of Employees, which is Empld.

4. Identify Entity Types Participating in Binary M: N Relationship Type:
For each binary M: N relationship type, create a new relation to represent such relationship. This new relation should include as foreign keys, the primary keys of the relations that represent the participating entity types.

Plus One Accountancy Chapter Wise Questions and Answers