Client Server Computing | Loksewa CAAN 078

Q. Briefly describe the concept of Client-Server computing. (5marks)

answer:

Client-server model is a distributed application structure that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients

Examples of Client-Server Model are Email, World Wide Web, etc.

Architecture:

Characteristics:

• Client-server computing works with request and response systems. The client sends a request to the server and the server responds with the required information. 
• Clients and servers must follow a common communication protocol so that they can easily communicate with each other. All communication protocols are available at the application level.
•  An example of a client-server computer system is a web server. Returns a web page to the client that requested the web page.

Benefits:
• All the data you need is centralized in one place - the server. This makes it easier to secure data and provide authorization and authentication. 
• The server does not need to be physically close to the client. However, the data can be accessed efficiently. 
• Nodes in the client-server model are easy to replace, upgrade, or move because all nodes are independent and only request data from the server.
limitations:
• If all clients request data from the server at the same time, it can become overloaded and cause network congestion. 
• The cost of setting up and maintaining a client-server model is quite high.

Notes on Data Warehousing and Data Mining | Loksewa CAAN 078

Q. Write a brief note on Data Warehousing and Data Mining. (5 marks)

answer:

 Data Warehouse

A data warehouse is a subject-oriented, integrated, time-variant and non-volatile collection of data in support of management's decision making process.

A data warehouse is constructed by integrating data from multiple heterogeneous sources that support analytical reporting, structured and/or ad hoc queries, and decision making. Data warehousing involves data cleaning, data integration, and data consolidations.

The information gathered in a warehouse can be used in any of the following domains :

• Tuning Production Strategies
• Customer Analysis
• Operation Analysis

 Functions of Data Warehouse :

1. Data Extraction
2. Data Cleaning
3. Data Transformation
4. Data Loading
5. Refreshing

Data Warehouse Applications

• Financial services
• Banking services
• Consumer goods
• Retail sectors
• Controlled manufacturing

Architecture of Data Warehousing

Data Mining

Data mining refers to extracting or mining knowledge from large amounts of data. The term is actually a misnomer. Thus, data mining should have been more appropriately named as knowledge mining which emphasis on mining from large amounts of data.

It is the computational process of discovering patterns in large data sets involving methods at the intersection of artificial intelligence, machine learning, statistics, and database systems. The overall goal of the data mining process is to extract information from a data set and transform it into an understandable structure for further use.

 The key properties of data mining are

•   Automatic discovery of patterns
•  Prediction of likely outcomes
•  Creation of actionable information 
• Focus on large datasets and databases

Data mining involves six common classes of tasks:

• Anomaly detection
• Association rule learning
• Clustering 
• Classification
• Regression
• Summarization

Data Mining Applications

• Market Analysis and Management
• Corporate Analysis & Risk Management
• Fraud Detection

Architecture of Data Mining

Data Types in Database Management System | Loksewa CAAN 078

 Q. Briefly describe the different data types used in the Database Management System. (5marks)

answer:

 Datatypes defines the domain of the columns in the table or variables in the code. They define whether the column or variable contains numbers, alphabets, Boolean values etc.

There are 6 inbuilt data types in DBMS. They are:

1. Scalar data types 

They are used to store the numeric column values or numeric variables. For example: If we have a column PHONE NO. in a table. This column can have only numbers in it. We cannot insert any date or alphabets into it. Hence we declare this column as NUMBER. This restricts the user while they try to insert any other values other than number. This is one of the mechanisms to maintain the domain constraint of a column.

It is subdivided into four types: Character, Numeric, Date/Time and Boolean.

2. Composite data types or User Define data types

Depending upon the need of the program, the programmer combines one or more datatype variables into form a one variable. This type of variables will have multiple same or different base datatypes defined in it. This type of datatypes is known as composite or user defined datatypes.

 For example, Record is one of the composite datatypes. It can have any number of datatypes within it

3.Reference data types

This datatype refers to the existing data in the program. It acts like pointers to the variable. One of the examples of reference datatype is refcursor. They are the cursor variables used to reference and access the static cursor. We can pass this variable to procedures / functions and get the values from function as a refcursor. In short it acts a variable, but reference to the query defined at the runtime.

4.LOB data types

These types of datatypes are used to store very large amount of data in a column / variable. It can store file like music, graphics etc. We have following types of LOB datatypes: BFILE, BLOB,CLOB, NCLOB

5.Unknown Column types

As we have seen this in the user defined datatypes to declare the variables. This is called unknown columns because this type of datatypes is not base datatypes and is defined by the user or tables. The programmer does not predict the datatype of it just by seeing name or declaration. S/He has to see the definition of record datatype to understand it. It is  subdivided as: %TYPE, %ROWTYPE, %ROWID.

6.User Define data types  

These datatypes are defined by the programmer while coding using the above base datatypes. They define new datatypes to ease their coding. This is can be considered as composite datatype too.

File system and Database management system |Loksewa CAAN 078

 Q. What are the major difference between a file system and a database management system? 5 marks

DBMS(Database Management System) : 
Database Management System is basically software that manages the collection of related data. Example: MySQL, Oracle, MS SQL server etc.

File System : 
The file system is basically a way of arranging the files in a storage medium like a hard disk. Example: NTFS(New Technology File System), EXT(Extended File System)

The difference can be summarize as:

File System	DBMS
It is a software application that organizes and maintains files on a storage device. It manages the storage and retrieval of data.	It is a software application that allows you to access, create, and manage databases.
Redundant data is present	No presence of redundant data
Data consistency is low in the file management system.	In DBMS, the data consistency is high
Storing and retrieving of data can’t be done efficiently in a file system.	DBMS is efficient to use as there are a wide variety of methods to store and retrieve data.
File system is relatively cheaper as compared to DBMS.	DBMS is costlier as compared to a file system.
The centralization process is hard in File Management System.	Centralization is easy to achieve in the DBMS system.
There is no efficient query processing in the file system.	You can easily query data in a database using the SQL language.

Bios and Its Function | CAAN Senior Assistant IT | 078 question paper

Q.  What is BIOS? Briefly discuss its  functions. (1+4) marks

answer: 

The BIOS, which stands for Basic Input/output System is a piece of software, normally stored in non-volatile memory (flash) or ROM (Read-Only Memory).

The functions of BIOS can be mentioned in following points:

CMOS and BIOS first check the settings between each other; later the computer is turned on, all settings in CMOS are read and executed.

The BIOS then loads a computer driver to interface between the operating system and connected devices.

BIOS then clean up all the CPU registers and make them ready for use.

Afterward, the BIOS check all the hardware devices, including the keyboard and mouse, and test them, a process known as POST or Power-on Self-Test.

During the POST process, you press a special key with the help of keyboard by which a set of settings appear in front of you, which is known as the BIOS setting.

This is the first setting that the BIOS load.

Later finds a BOOTABLE medium, it loads essential files into the RAM, and then the computer is on, and we are able to view the desktop.

Apart from this, It saves the most important basic input and output programs of the computer, system settings and the self-checking and self-triggered programs. The main function of it is to provide the basic and direct hardware settings and controls to the device.

The most important function of BIOS is to boot the operating system of the computer. When the computer is on, then BIOS performs the task such as decide from which device system  is the boot, conduct power-on-self-test and so on.

Software and Its types | CAAN loksewa 078 Question paper

Q. What do you mean by software? Briefly describe various types of software. (2+3)marks.

answer:

A software or computer software essentially a type of programs which enable the users to perform some particular specific task or actually used to operate their computer.

A software plays a key role of a mediator between the user and the computer hardware.

It provides a set of instructions to execute a user’s commands and tell the computer what to do. For example like MS-Word, MS-Excel, PowerPoint, etc.

Generally, there are two main classifications of software, which are namely, System Software along with the Application Software.

source: freepik.com

1.System Software

System software is software that directly operates the computer hardware and provides the basic functionality to the users as well as to the other software to operate smoothly. In simpler word, it can be said that system software is essentially an intermediator or even a middle layer between the user as well as the hardware.  so system software converts the human-readable language into machine language and vice versa.

Some features of system software are:

• closer to the computer system.
• written in a low-level language in general.
•  difficult to design and understand.
• fast in speed(working speed).

Further System Software is divided in main 2 subtypes. They are:

A) Operating System

 it is  a collection of software which handles resources as well as offers general services for various other application which actually run over them. There are different types of operating systems like embedded, real-time, distributed, single-user, multi-user, mobile, internet and much more.

B) Language Processor

Language processor converts the human-readable language into a machine language and vice versa. It converts programs written in high-level programming languages into machine readable i.e. source code to object code/machine code. 

 C) Device Driver

It is a program or software that controls a device and helps that device to perform its functions. All devices like mouse, modem, etc. needs a driver to connect with the computer system eternally.

2. Application Software

Software that performs special functions or provides functions that are much more than the basic operation of the computer is known as application software. They are also popularly known as end-user programs or even productivity programs which assist the user in completing various tasks like designing graphics, maintaining accounts, carrying out calculations or even playing computer games.

Features of Application Software:

• performs more specialized tasks like word processing, spreadsheets, email, etc.
• more interactive for the users
• easy to design and understand
•  written in a high-level language in general

Like system software, application software is also subdivided into following types:

A) General Purpose Software

These software are used for a variety of tasks and it is not limited to performing a specific task only. For example, MS-Word 

B) Customized Software

These software are  used or designed to perform specific tasks or functions or designed for specific organizations. For example, railway reservation system 

C) Utility Software

These software are used to support the computer infrastructure like analyzing, configuring, optimizing and maintaining the system. For example, antivirus, memory tester, disk repair, registry cleaners, disk space analyzer, etc.