Computer studies analysis of questions and answers

List three ways by which you can provide a common link or relationship between the tables in a database software

15/11/2021

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(a) List three ways by which you can provide a common link or relationship between the tables in a database software. (3mks)

one -to -one
one – to – many
many – to – many

(b) What is referential integrity (1mk)

relationship based on primary and foreign keys
a feature that governs the nature of records in a one – to – many relationship between tables in database

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With the aid of a diagram, describe the Hierarchical Database Model.

13/1/2021

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With the aid of a diagram, describe the Hierarchical Database Model.

Data items are arranged in a tree like format.

Access is through a single path and all from one single item called the root component

(b) List three factors that should be considered when developing a database application and give reasons why each should be considered.
Factors

Complexity of data/user needs/user friendliness
Security and integrity
Complexity of DBMS
Volume of data/size
Software compatibility with existing DBMS
Cost of the data base

Reasons

Complexity of data - Complex data requires complex DBMS.
Security and integrity - Data which is intended to be secured in terms of access, can be handled by complex DBMS which provides for such requirements.
Complexity of DBMS - Complex DBMS do require complex skills, hence more training. It is therefore costly to run/use such system.
Volume of data - Voluminous data require to be ran on stable application.
They also take up extra computer system resources.
Software compatibility - enables pre-existing databases to be exported to the new one.

(c) (i) Name three types of validation checks during data entry in data processing.

Field type/data type
Field size
Format
Reasonableness
Range constraint
Presence check

(ii) Differentiate between primary key and index key as used in databases.

Any index key is a database feature used to speed up search and sort operations in a table; whereas
A primary key is a field that enforces uniqueness in a table so that one record is not entered twice or a primary key is a field that uniquely identifies each record.

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State three reasons why it is important to define datatypes of fields in a database correctly.

8/1/2021

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State three reasons why it is important to define datatypes of fields in a database correctly.

Reasons for defining datatypes in databases

Memory use optimisation when the program is loaded;
Assist in trapping errors during data input;
So that appropriate computation can be performed;
Increase speed of processing.

State three reasons why it is important to define datatypes of fields in a database correctly.

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Figure 1 shows relationships between tables in a database.

7/1/2021

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Figure 1 shows relationships between tables in a database.

Identify two primary and two foreign keys used in the relationship.

Primary keys

TermiD
StudentiD

Foreign keys

TermCode
StudID

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State three hardware devices that may be required to connect a computer to an existing local area network.

7/1/2021

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A) State three hardware devices that may be required to connect a computer to an existing local area network. (3 marks)

A network adapter/network interface card
Network medium/cable
RJ45 connectors/BNC/ST connector/SC connectors/Fibre local connector
Data points (sockets to plug in the cable)
Switch/Hub
Access point/TP link

B) A publisher intends to use a desktop publishing programme to create a publication which is to have many graphics. State three ways in which the graphics may be acquired for this purpose. (3 marks)

Using digital camera
Scanning the graphics from other sources
Downloading from the internet
Drawing from scratch/Drawing tools
Clip art
Another file

C) Interpret each of the following spreadsheet formula:

(i) = countif(D2:D9, “>“&B4) (2 marks)

(ii) sumif(B3 :B 11, “4M”, D3 :D11) (2 marks)

(i) = Countif (D2 : D9, “>“ & B4)

Count those value in the range D2 :D9 with values greater than the value in cell B4).

(ii) = Sumif (B3 : B11, “4M” D3 : D11)

Sum the values in the cell range D3 : D11 for records whose
corresponding values in cell range B3 : B11 equals to “4M”

(D) The following are the fields of products table in a database created to store records of products manufactured in a factory:

product number
product name
price
product description

I. State the appropriate data type for each field. (2 marks)
II. State three properties to be put in place during table design to ensure integrity of the data entered. (3 marks)

I) Product Number — Number/Autonumber/Text

Product Name — Text/string
Price — Currency/Number
Product Description — Memo/Text/String

(II) Properties that can be set in the table design

Data type
Validation/Validation rule
Input mask
Setting required/null value status
Field size
Caption

(D) The following are the fields of products table in a database created to store records of products manufactured in a factory:

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A school keeps student records in a database. The data is coded before entry.

6/1/2021

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A school keeps student records in a database. The data is coded before entry.

State three reasons why the coding is necessary.

Indexing becomes easier.
Minimises on memory used.
Ease of data entry.
Reduce s redundancies/double entry.
Speedy searches due to shortened comparisons
Simplifies validation

A school keeps student records in a database. The data is coded before entry.

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With the aid of a diagram, describe the Hierarchical Database Model.

5/1/2021

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With the aid of a diagram, describe the Hierarchical Database Model.

(b) List three factors that should be considered when developing a database application and give reasons why each should be considered.
(c) (i) Name three types of validation checks during data entry.
(ii) Differentiate between primary key and index key

RESPONSES

(b) List three factors that should be considered when developing a database application and give reasons why each should be considered. (i) Name three types of validation checks during data entry. (ii) Differentiate between primary key and index key

Data items are arranged in a tree like format.
Access is through a single path and all from one single item called the root component.
(b) Factors .

Complexity of data/user needs/user friendliness
Security and integrity
Complexity of DBMS
Volume of data/size
Software compatibility with existing DBMS
Cost of the data base

Reasons

Complexity of data - Complex data requires complex DBMS.
Security and integrity - Data which is intended to be secured in terms of access, can be handled by complex DBMS which provides for such requirements.
Complexity of DBMS - Complex DBMS do require complex skills, hence more training. It is therefore costly to run/use such system.
Volume of data - Voluminous data require to be ran on stable application. They also take up extra computer system resources.
Software compatibility - enables pre-existing databases to be exported to the new one.

Field size
Format
Reasonableness
Range constraint
Presence check

(ii) Any index key is a database feature used to speed up search and sort operations in a table; whereas a primary key is a field that enforces uniqueness in a table so that one record is not entered twice or a primary key is a field that uniquely identifies each record.

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What is an information system?

5/1/2021

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What is an information system?

(a) (i) What is an information system?
(ii) State two roles of an information system.
(b) Describe the following file organisation methods:
(i) random file organisation;
(ii) sequential file organisation.
(c)The following records were extracted from two files that contained student data.

(i) Which of the two files above represents a Transaction file?
(ii) Give a reason for your answer in c(i) above.
(iii) Name the other type of file represented above.
(d)An airline uses an information system whereby if a passenger at station A books a plane seat,this transaction is immediately shown at stations A and B such that no other passenger can book the same seat.
(i) Identify this data processing mode.
(ii) State two advantages and two disadvantages of this data processing mode.

RESPONSES

(a)(i) Information system is an arrangement of people, data, processes, communication and IT that interact to support problem solving.
(ii) Improve day-to-day operation

Support problem solving
Support decision making needs for management
Data capture
Processing data into information
Data security
Storing of data/information

(b) (i) Stored and retrieved according to their disk address which is generated by use of an algorithm or formula i.e. stored randomly, accessed randomly.
(ii) Method of storing or retrieving information that requires the program to start reading at the beginning and continue until it finds the desired data.
(c) (i) File B.
(ii) Transaction file: It contains data which is regularly added.
Has data/fee payment .
(iii) Master File: It contains records that do not change regularly like in file A.

(d) (i) Real time processing.
(ii) Advantages

Information is readily available for instant, decision making.
Updating is done instantly when transaction occurs.
Auditing is easier.
It is accurate
Prevent double booking

Disadvantages

Complex - difficult to configure/set up.
Expensive to acquire and maintain.
Errors that occur are difficult to correct

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Describe the following types of relationships as used in Database design: One-to-one and One-to-many.

5/1/2021

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Describe the following types of relationships as used in Database design:One-to-one and One-to-many.

(a) One-to-one;

An association between two tables in which the primary key value of each record in the primary table corresponds to the value in the matching field or fields of one and only one record in the related table.

(b) One-to-many.

An association between the tables in which the primary key value of each record in the primary table corresponds in the value matching field or fields of many records in the related table.

Describe the following types of relationships as used in Database design: One-to-one and One-to-many.

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State four activities of the planning stage of systems development

4/1/2021

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(a) State four activities of the planning stage of systems development. (4 marks)

Activities at the planning stages

Identify opportunity for the new project.
Analyse feasibility to establish the viability of the project.
Develop a work plan.
Identify appropriate staff to work in the project.
Control and direct the project.

State four activities of the planning stage of systems development

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State the purpose of each of the following in database design.

4/1/2021

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State the purpose of each of the following in database design.

(a) input mask

Input mask: Is a layout/format that filters the data that can be entered in a field.

(b) default value

Default value: Used to specify the value that is automatically entered in a field when a new record is created.

State the purpose of each of the following in database design.

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Using two examples, explain the term field properties as used in database design.

3/1/2021

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Using two examples, explain the term field properties as used in database design.

(b) Below is an extract from a hospital database table.

(i) State with reasons the most suitable data types for the following fields:

(I) patient No;
(II) date registered;
(III) amount paid;
(IV) remarks.

(ii) Which would be the most appropriate primary key field for the above table?
(iii) What is the purpose of a primary key field in database design?
(iv) Describe how information about patients who registered after 09/08/06 can be extracted from the database.

(a)Field property:

Specifies details related to fields and table entries expected e.g. field size, format, decimal places etc.

(i)

(I) Patients No. - Data type - Text
Reasons — it combines both numeric and alphanumeric characters.
(II) Date -Date type -Date
Reason — Data type can be manipulated mathematically, e.g number of moths can be calculated between two dates.
(III) Amount paid — Data type - Currency/Numeric
Reason — it can be manipulated mathematically.
(IV) Remarks - Data type - Memo
Reasons — the content may be lengthy e.g. giving a paragraph.

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Distinguish between Real, Integer and Character data types as used in programming

3/1/2021

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Distinguish between Real, Integer and Character data types as used in programming ( 3mks)

Real
Constant is represented in two parts, a mantissa part and an exponential part e.g. 123.456
Integer
Constant must have at least one digit written without a decimal Point.
Character
A data component that represents a single letter or symbol

Name two types of relationships that can be applied in database design.

2/1/2021

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Name two types of relationships that can be applied in database design (2mks)

One to one
One to many
many to many

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State three operations that can be performed on relational database files.

1/1/2021

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State three operations that can be performed on relational database files

Sorting
Querying
Report creation
Performing calculations
Indexing

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(a) List three ways by which you can provide a common link or relationship between the tables in a database software. (3mks)

(b) What is referential integrity (1mk)

With the aid of a diagram, describe the Hierarchical Database Model.

State three reasons why it is important to define datatypes of fields in a database correctly.

Figure 1 shows relationships between tables in a database.

​A) State three hardware devices that may be required to connect a computer to an existing local area network. (3 marks)

​B) A publisher intends to use a desktop publishing programme to create a publication which is to have many graphics. State three ways in which the graphics may be acquired for this purpose. (3 marks)

​C) Interpret each of the following spreadsheet formula:

​(D) The following are the fields of products table in a database created to store records of products manufactured in a factory:

A school keeps student records in a database. The data is coded before entry.

​State three reasons why the coding is necessary.

With the aid of a diagram, describe the Hierarchical Database Model.

RESPONSES

What is an information system?

RESPONSES

Describe the following types of relationships as used in Database design:One-to-one and One-to-many.

(a) One-to-one;

(b) One-to-many.

​​(a) State four activities of the planning stage of systems development. (4 marks)

State the purpose of each of the following in database design.

(a) input mask

(b) default value

Using two examples, explain the term field properties as used in database design.

​Distinguish between Real, Integer and Character data types as used in programming ( 3mks)

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A) State three hardware devices that may be required to connect a computer to an existing local area network. (3 marks)

B) A publisher intends to use a desktop publishing programme to create a publication which is to have many graphics. State three ways in which the graphics may be acquired for this purpose. (3 marks)

C) Interpret each of the following spreadsheet formula:

(D) The following are the fields of products table in a database created to store records of products manufactured in a factory:

State three reasons why the coding is necessary.

(a) State four activities of the planning stage of systems development. (4 marks)

Distinguish between Real, Integer and Character data types as used in programming ( 3mks)