IBPS (IT Officer) Syllabus and Study Material

Hi friends, there are few days left for IBPS Specialist Officer exam for year 2017. At this stage, all aspirants want to make sure they are not leaving any topic uncovered for IBPS IT officer position. Please refer the link for the syllabus of Specialist Officer exam of IBPS.

Topics for IBPS IT Officer

While preparing for IT officer post of IBPS exam, aspirants are bit confused about how to cover all topics and pass the exam with good scores. So, here I’ll be sharing study material with a questionnaire set to practice for the exam. I am sharing one chapter/lesson of IT officer syllabus each day, IBPS/Any bank IT officer aspirants can go through these chapters. This way, you guys can track the record of your progress as well as can increase the chances of your selection by daily practicing on the questionnaire.

I’ll also share the last 5 years question papers in my next post. Please stay tuned. Also, please share your comments below if you feel I am missing any IT topic in my post 🙂

Download Admit card of IBPS SO exam

Topics to be covered:

Chapter 1: Malwares and Virus Types

Chapter 2 : Computer Networks and topologies

Chapter 3 : Different Standards – IEEE, ISO

Chapter 4 : Computer Network and architecture

Chapter 5: SQL Basics

Chapter 6: Operating System

Chapter: DBMS Concepts

SAS Basics : Learn Creating SAS Dataset

Hi all, I  know I am bit late actually very late in posting this blog post. So, we will be learning SAS today and I am covering some basics of SAS.

So, in order to learn it first there are multiple things that we will cover. What is SAS and why it is used.

SAS is a statistical and business analytics package tool that help you derive insights from the data and visualize the output to client. Yeah too much in a statement…?? 😉 No problem we’ll understand all of these things here.

Firstly, let’s check what makes SAS and what are the primary components of it:

Primary components of SAS:

1. SAS Library – This is just a SAS folder where in you will be keeping all your sas dataset or the files you would like your system to be read

2. SAS Editor Section – Here you will be writing your SAS code. SAS coding is more SQL like. If you want to learn SQL also, check my article: Learn Basics of SQL

3. SAS log section – This SAS component will give you all the information regarding the changes your code have made or the information from your imported SAS dataset. For example, the count of observations and rows, the data type of these fields and length. This component is very important to check any issues related to data type issue while performing data merging or transfer from SAS ton Teradata.

4. SAS debug section – This section enables the SAS developer to do any sort of debugging over the issue. There are various options available that lets you check the issue by filtering and sorting record.

How to Create SAS Library :

– This is the very first step that you will be doing in SAS Enterprise Guide or SAS Basic. There is a default SAS Library called – “WORK” library. This keeps all the temporary data. So, there are two types of libraries:

1. WORK
2. User Defined Library

Work – Keeps all temporary data of that particular SAS session only. Once the system is log off, all the data is erased. So, better you save it in some user defined library by before loosing it…LOL

User Defined Library – You can create library by following the syntax given as following:

Libname [Your Library Name] “Location where you want to save your files or SAS Dataset”

example: Libname AA “C://User/John/Documents/New Datasets/”

This will save all the SAS dataset in New Datasets folder.

Now Learn the three major components of SAS Code:

Steps of SAS:

1. Data Step
2. Proc Step
3. Run Step

So, for today this is all folks to be learnt in basics of SAS :p

If you want to learn more about it, let me know in comments. Thanks 🙂

Date Time Functions in SQL and the Use of Date Time Functions

Date Time functions in SQL

There are various Date time functions available in SQL which allow us to create trigger based on it. Date time function allow us to check whether an input string is a date or not. Also, we can check what’s the day or week number on a specific date using date time function.

Date Time

Let’s check various date time function available with us:

  1. IsDate

The isDate function is used to check whether the input string is a date or not.

Command: Select isDate(“2012-05-30”), it will return 1

If the input string is not a date, the IsDate date time function will return zero.

The isDate function works well on date, time and datetime datatype but not with datetime2 (timestamp with nanoseconds)

2. Day()

This date time function returns the “day number” of the specified input date string.

Command: Select Day(“2012-02-30 02:35:35”) – Returns 30

3. Month()

This sql date time function returns the “month number” of the specified input date string.

Command: Select Month(“2012-02-30 02:35:35”) – Returns 2

4. Day()

This sql date time function returns the “day number” of the specified input date string.

Command: Select Day(“2012-02-30 02:35:35”) – Returns 30

5. DateName()

The DateName() date time function returns a string value while other date time functions return integer value.

There are various attributes that can be used with the DateName() function. let’s me share some examples of it here:

  1. DateTime(Day, “Date value”|”DateTime Value”) – This function returns the day value (exception it is integer)

Command: Select DateTime(Day, “2013-05-23”) – the output will be 2

2. DateTime(WeekDay, “Date value”|”DateTime Value” – This function returns the week day value

Command: Select DateTime(WeekDay, “2013-05-23”) – the output will be Saturday.

3. DateTime(Month, “Date value”|”DateTime Value”)  – It returns the month value as a string

Command: Select DateTime(Month, “2013-05-23”) – the output will be May.

6. Datepart()

The DatePart() function works similar way as DateName function to find out the weekDay. the only difference between DatePart() and DateName() function is Datepart() returns an integer.

e.g. Select DatePart(WeekDay, “2013-05-25”) will return 2 if it is Tuesday

7. DateAdd()

This sql function will add day, month or year according to the specified value.

Command: Select DateAdd(Day|Month|Year, integer value of addition, Date Value)

e.g. Select DateAdd(Day, 10, “2013-05-20”) – This will output “2013-05-30”

Date Diff

8. DateDiff()

This sql function will add day, month or year according to the specified value.

Command: Select DateDiff(Day|Month|Year, Date value 1,Date value 2)

e.g. Select DateAdd(Month, “2013-05-20″,”2013-01-20”) – This will output 4

Cast and Convert Functions in SQL

Cast and convert functions allow you to convert one data type into another.

Syntax of Cast function:

Select cast(Column_name as Data type)

e.g. Select cast(date as nvarchar)

Syntax of Convert function:

Convert function lets you choose style parameter for string values only. The style feature is not available in cast function. By styling I mean a user defined format in which the output is required.

e.g. Select convert(data type, column_name, style)

There are some specific style codes like 103 means : dd/mm/yyyy. Thus the following example:

Select convert(nvarchar, DateOfBirth, 103)

Stored Procedures and String Functions in SQL

Hola friends, let’s understand what are stored procedures and the benefits of using it. I hope you have learnt some basics of SQL before this. Learn basics of SQL in my previous post.

What are Stored Procedures?

Stored procedures are a set of instructions that need to be instructed again and again. In SQL we can save this frequent instructions as a procedure and call them by just their name.

 

Stored Procedures

How to create Stored Procedures?

To create stored procedures, simply use the Create Proc/Procedure Procedure_name command.

We can also pass parameter in a stored procedure. The parameters can be of two type:

1. Input (Used to take input)

2. Output (used to print output) – The output keyword must be specified as output in the description.

One example of the stored procedure is shown in the below image:

 

Stored-Procedure1

Running the Stored Procedures:

The command used to execute a stored procedure is: EXEC|Execute Procedure_name

e.g. Exec HumanResouces.uspFindEmployee “123” (Here 123 is the value for the @BusinessEntityID input parameter.

Stored Procedure with Output Parameter

An example of output parameter is:

Create Proc spGetEmployeeCount

@LastName int

@EmployeeCount Output

As

Begin

Select @EmployeeCount =Count(*) from emp where LastName = @LastName

End

Executing Stored Procedure with Output Parameter:

To execute the stored procedures with output parameters, it is very important to declare the output variable first. To declare the output variable, use the following command:

Declare @OutputVariableName Datatype

Exec Storedprocedurename Input parameter, Output Parameter Out|Output

Print@OutputVariableName

e.g.

Declare @TotalCount Int

Exec spGetEmployeeCount @LastName = “Male”, @TotalCount Out

Print@TotalCount

Benefits of Stored procedures:

  1. The execution plan can be reused

When a normal statement is executed, the path like first few columns are selected, then refined through where clause and then ordered. This is called a kind of execution plan. So, we can save time through stored procedures.

e.g. Select name, gender from Emp

when id IN(12, 14, 15)

order by name

A normal statement if executed with different parameters, use different execution path. However Stored procedures uses the same execution path even with different variable values.

2. Reduced Network Traffic

Since Stored procedures allows code re-usability, the sql instructions takes less time and space while utilizing network bandwidth. Thus network traffic is reduced.

3. Easy Maintainability using Stored Procedures

Maintenance becomes easy. A change in stored procedure is easy rather than finding similar statements at various places and then modifying the code.

4. Code Re-usability

The instruction that will be required again and again need not to be typed again. We just have to create a stored procedure with that statement and this will help us in reusing the code in less time and space.

5. Better Security

The database can be huge and we don’t want everyone to give access to every user in the network. So, build procedures on the specific table to which the user wants access. This way we will be able to provide better security.

6. Avoid SQL Injection Attack

Stored procedures also helps in avoiding SQL injection attacks. To know more about SQL injection attacks, go to the link.

Learn basics of SQL here

String Functions in SQL

  1. Left function:

This string function in sql returns integer values from the left.

command: select left(string, integer count)

e.g. Select left(“abcd”, 3) – Result will be “abc”

2. Right Function

This string function in sql returns integer values from the right of a string/column value.

command: select left(string/column, integer count)

e.g. Select left(“abcd”, 3) – Result will be “bcd”

3. CharIndex

This sql function returns the index of the character value.

command: Select charindex(“a”, “abcd”) – answer would be 1

4. Len

This function the total length of a string or column value of string type.

command e.g. : Select len(“abcd”) – answer would be 4

Note: This sql string function will not count the blank values at the end of a string.

5. Substr

This sql function is used to select a substring value from a string.

Command: select substr(“string value”|column name, position to start, length of fetch character

e.g. Select substr(“abcd”, 1, 3) – answer would be “abc”

We can also choose negative indexing here. A -1 indicates from the right.

6. Replicate

Replicate function replicates a specific string to the specified number of times.

command: Select replicate(“string”, number of times to replicate)

e.g. Select lastname + replicate(“*”,5)

This command will repeat the * five times in lastname. Let’s say the lastname is “John” then the output is: “John*****”

6. Space

This sql function will insert space to the specified number of times between column values.

command: Select Lastname + Space(5) +First name – This command will introduce a 5 character space between first name column value and last name.

7. PatIndex (or Pattern Index)

PatIndex works the same way as charindex by telling the first occurrence. However, PatIndex allows you to use wildcard. You can’t use wildcard with CharIndex.

e.g. Select PatIndex(“aaab”, “abcaaababc”) – The answer would be 4

If it do not find any matched string, the sql string function returns zero.

8. Replace

This string function replaces a string into another one.

Command: Select(String, “value to replace”, replacement value”)

e.g. Select(“abcd.com”, “.com”, “.net”) – The result will be “abcd.net”

9. LTRIM

This string function is used to trim leading blanks from the beginning.

Command e.g. : Select LTRIM(LastName)

10. RTRIM:

This sql function trims the trailing blank values.

e.g. Last Name : “abcd  ”

Select RTRIM(LastName) – the result will be “abcd”

11. ASCII:

This SQL function returns the ASCII code of the string value.

Command: Select ASCII(string value)

e.g. Select ASCII(A) – The answer would be 65

12. CHAR

This SQL function returns the character value from the integer ASCII code.

Command: Select CHAR(Integer value)

e.g. Select CHAR(65) – The answer would be A

13. STUFF

This sql function replaces a specific string value at the specified position by replacing the characters up to length value. It is kind of masking.

Command: Select STUFF(Column, Starting position, length, String to be used as replacement)

e.g. Select STUFF(LastName, 1, 3, “**”)

If the last name is “JohnMarcel”, the output of stuff function will be “***nMarcel”

SQL Basics and Queries : SQL Tutorials

What is a Database?

Database is an organized collection of related information. In daily world we deal with lots of data. In this internet technology more and more data is getting produced these days. We have multiple database management systems available with us to manage, store and update this enormous data in convenient way. e.g. Oracle, Sybase, Microsoft SQL server management studio etc.

DBMS and SQL

DBMS and SQL

DBMS (Database management server) is a collection of software tools used to manage, update, retrieve the data from the database. SQL (Structured query language is used to connect the DBMS with the database.

DBMS

All queries have been executed on the Microsoft SQL Server management Studio version 17.0. SSMS is a client tool and not the server. It is rather used as a tool to connect to the database server.

Settings: Local Host

Connect: Database Engine

Use SQL authentication username and password

SQL Databases:

In Microsoft SQL Server Management Studio you will find two types of databases:

  1. System Database
  2. User created Database

-System database can’t be deleted

SQL Command Types:
  1. DDL (Data Definition language) – Used to define/create database object
  2. DML (Data manipulation language) – Used to insert values, update and delete values from the database object created by DDL commands.
  3. TCL (Transaction Control language) – Used to control transactions through Commit and Rollback commands

SQL DDL Commands – data definition language (Create, Alter and Drop commands)

1. Creating a database:

Database can be created either using GUI or through SQL query in SSMS.

Create statement is used for this purpose: Create [Database Object] [Database Object name]

Ex. Create Database db1 (this statement will create a database with name db1)

Whenever we create a database, two types of files are created with it: 1. .MDF file (contains actual data) 2. .LDF file (contains log file)

2. Modify a Database:

Alter statement is used to alter a sql database object.

Alter Command:  Alter [Database Object] [Database Object name] Modify Col1 = Value

E.g. Alter Database db1 Modify Name = db2 (this will change the name of the database)

Renaming through stored procedure: sp_renameDB [Old database name] [New database name]

e.g. sp_renameDB db1 db2

3. Dropping a Database:

Drop statement is used to delete a database completely from the system(.mdf and .ldf files are also deleted with it)

Drop command: Drop [Database Object] [Database Object name]

e.g. Drop Database db1 (this will delete database db1)

Note- If a database is getting used by any other user, make sure that database is not getting used by any other database. Else an error will be generated

Resolve this single user thing, use this command:

Alter Database db1 set Single_USER with Rollback immediate

(Rollback immediate, rollback any commands and delete the database immediately)

SQL DML Queries : Insert, Update, delete

1. Create a Table:

Command: Create Table [table name] ([column name] [data type of column] [constraint])

e.g. Create table t1(ID int NOT NULL Primary Key, Gender nvarchar(20) NOT NULL)

This command will create a table with name t1 and 2 columns ID and Gender of INT and nvarchar datatypes respectively. nvarchar is a UNICODE data type and store 2 bytes per characters, while varchar stores 1 byte per character.

In order to store the table in a particular database use the following command:

Use [database name]

Go

Create table command….

Primary Key – Can’t be null and must be unique. It uniquely identify each row in the table

Foreign key– It can contain null values and it references primary key present in some other values (basically the column in which it looks for a value). Foreign key is used to establish relationship between two tables. It is used to enforce database integrity.

Create a Foreign key relation –

Alter table [table name] add constraint [constrain name] foreign key(foreign key column name) references [PrimaryColumn Table Name] (primary key column)

e.g. Alter table tb1 add constraint tb1_genderid foreign key(tb1) references tb(id)

Note- Constraint name should make sense like tablename_columnName

2. Select all values of a table:

Command: Select * from [table name]

To select all tables of a database choose:

Select * from dual (dual refers data dictionary)

3. Insert values in a table :

Insert command is used to insert values in a table: Insert into [table name] (col 1, col 2, …) Values(col 1 value, col 2 value,…)

e.g. Insert into a1(id, name, gender) values(11, “ss”, “male”)

4. Adding a Default value in a column:

We can assign default values to a column rather than assigning Null values:

Alter table [table_name] add constraint constraint_name Default [default value] For [column name]

e.g. Alter table tb1 add constraint tb1_gender default 2 for gender

This command will assign default value 2 to column gender if value not explicitly defined.

5. Adding a New column into table:

Command: Alter table [table name] add [column name] [column data type] [NULL|NOT NULL] add constraint [constraint name] Constraint

Alter table tb1 add Address nvarchar Not Null add constraint tb1_address default ‘xyz’

This command will add one column Address to the table tb1 that don’t accept null value. Also, default value of ‘xyz’ will be assigned to it.

6. Dropping a Constraint:

Command: Alter table [table name] Drop Constraint [constraint name]

e.g. Alter table tb1 drop constraint tb1_gender

This will drop the constraint.

7. Delete a Table record:

To delete a table record, we use delete command:

Delete from [table name] where column1=”column value”

Note: Where clause is used to put some condition on search selection

However, you can’t delete a table record if the table is getting used by some other user. There are some cascading referential integrity constraint imposed on foreign key constraints.

8. Cascade Referential Integrity Constraint:

We can choose options if a foreign key constraint reference is getting deleted. Four options are there:

  1. No Action : This will simply generate an error if a record from primary key table is deleted that has some value in foreign key table.
  2. Cascade: This option will delete all the foreign key records that are related to primary key will be deleted
  3. Set NULL: This option will set the foreign key dependent value to Null.
  4. Set Default: This option will set the foreign key dependent value to default values provided to the column.

9. Adding a Check Constraint:

This constraint is used to enforce value checks on column. For e.g. The value in the age column>4

Command: Alter table [table name] add constraint [constraint name] check (boolean expression)

e.g. Alter table tb1 add constraint tb1_age_check check(AGE>0 AND AGE<30)

This command will only let you add age between 0 and 30 in the Age column.

Note: The check constraint returns a Boolean value based on which the value is entered in the table. It also let you insert Null values because for Null values, check constraint returns “Unknown”.

10. Identity Column:

It is a column property in SSMS.

Identity column is a column to which values are automatically assigned.

Identity Seed: A value with which the identity column value starts

Identity Increment: The value with which identity column value is incremented.

Command: Create table stu(id int identity(1,1) Primary key)

This command will create a stu table having id as a identity column. The id column here will start from 1 and incremented by 1.

 

10. Setting up External Values/Explicit Value to Identity Column:

To set up external value in Identity column, add the following command before inserting values in table:

Command: Set IDENTITY_INSERT [table name] ON

Insert into table name(column list) values(1,”23″..etc)

11. Setting Off External Values/Explicit Value to Identity Column:

Command: Set IDENTITY_INSERT [table name] OFF

Insert into table name(column list) values(1,”23″..etc)

Note: To reset the identity column value, use DBCC command.

12. Unique Key Constraint:

Unique key constraint is used to enforce unique values in database. There is a slight difference between primary key and unique key.

Primary key values = Unique+Not Null

Unique constraint value = Unique + values can be null

Command: Alter table table_name add constraint constraint_name unique(column name)

or

Create table Stu(Name varchar(20) Unique)

13. Applying a Trigger:

Firstly let’s try to understand what a trigger is. A trigger is an sql instruction/set of instructions that will will cause an action once a specific condition occurs. For example: Inserting another row table 2 when a row is entered in the table 1.

Command:

Create Trigger [trigger_name] on [table_name] for Insert/Update/Delete/Condition

as

begin

[instructions]

end

14. Selecting values from table:

Select is a command used to retrieve records from a table.

  1. To fetch all records from a table:

Command: Select * from [table_name]

e.g. Select * from emp

2. Select specific columns from a table:

Command: Select [col_name_1], [col_name_2]… from [table_name]

e.g. Select name, age, id from Employee

3. Fetch all distinct records from a table:

Command: Select distinct [column_name] from [table_name]

e.g. Select distinct name from Employee

This command will help in fetching the distinct records from table Employee by Name column.

4. Fetch record matching a specific condition:

Where is used to apply a specific condition in the SQL command.

Command: Select * from table_name where column_name = condition value

e.g. Select name, id from employee where name=”John”

This command will fetch all the records from the table with name column value as john.

5. Fetch record not matching a specific condition (column value):

Command: Select * from table_name where col_name <> Column value

“<>” signifies as not equal to here. We can also use “!=” to compare values.

6. OR operator in SQL:

OR operator is used to specify two or more conditions together.

Command: Select * from table_name where col1=value OR col2=value

e.g. Select name, age, salary from Employee where name=”John” OR name=”Nick”

This sql command will fetch all the table records where name is either John or Nick

7. AND Operator in SQL:

AND operator is used to specify two and more conditions together.

Command: Select * from table_name where col1=value AND col2=value

e.g. Select name, age, salary from Employee where name=”John” AND age=”30″

This sql command will fetch all the table records where name is John and age is Nick

8. IN Operator in SQL:

IN operator is used to retrieve records where condition matches more than 1 value. (And you don’t want to use OR multiple times in a sql command)

Command: Select * from table_name where col_name IN(value1, value2, value3…)

e.g. Select * from Employee where age(21, 25, 30)

This command will fetch all the table record where age is either 21 or 25 or 30.

SQL Wildcards

SQL supports various kind of wild card characters to facilitate data retrieval in multiple ways. Please refer the image for all sql wild card characters.

Data Mining – Learn Data Mining, OLAP, OLTP and Clustering

Hi friends, let’s discuss the important concept of Data Mining and the four common tasks of data mining: Data Clustering, Data classification, regression and association rule learning.

This is an important topic to learn and adopt as a career option these days. Lots of people are trying their luck in this field by mastering the data analysis skills. It is a growing field and by 2020 the vacancy graph for professional data analyst, business analyst and data scientist will be at par.

Hope you guys have checked my previous post on Malicious Programs/Malwares for answering the questions related to this section.

Future Scope of Data Analyst:

Apart from future perspective, data mining is an important topic considering the various government exam vacancies for computer science professionals. So, I have tried to collect every important part of topic data mining in this blog.

If you guys want any other topic to be covered, please let me know by adding a comment. Now let’s first understand what Data mining and data analysis is.

data mining

What is Data Mining and the use of Data Mining?

Data mining is the process of extracting patterns from data. It is an important tool used by modern business to drive information from data. Data mining is currently used in marketing, profiling, fraud detection and scientific discovery etc.

Tasks of Data Mining:

  1. Data Clustering: It is the task of discovering groups and structures in the data that are similar in some way. Data clustering is performed without using known structures in data.
  2. Data Classification: Data classification is the task of generalizing known structures to apply to new data. Common algorithms related to data classifications are:   1.1. Decision tree learning

1.2.  Nearest neighbor

1.3.  Naïve Bayesian classification

1.4.  Neural networks

1.5.  Support Vector Machines

3. Regression: With Regression we attempt to find a function which models the data with the least error. There are different strategies related to regression models.

4. Association Rule learning: This learning is used to search for relationships between variables. I would like to share a big example of association rule learning:

With the help of association rule learning, Amazon displays the items frequently bought together to show as a recommendation. Thus helps the customers and increase its sales.

Approaches to Data Mining Problems:

  1. Discovery of sequential patterns
  2. Discovery of patterns in time series
  3. Discovery of classification rules
  4. Neural Networks
  5. Generic Algorithms
  6. Clustering and Segmentation

Goals of Data Mining and Knowledge Discovery:

  1. Prediction: Data mining can show how certain attributes within the data will behave in future.
  2. Identification: Data mining can be used to identify the existence of an item
  3. Classification: Data mining can partition the data so that different classes or categories can be identified
  4. Optimization: Data mining can be used to optimize the use of limited resources such as time, space, money or materials to optimize the output

What is OLTP (Online Transaction Processing)?

In order to understand OLTP, it is very important to be aware about Transaction and transaction system. So, what is a transaction? What are the properties of transaction system? Let’s analyze the theory of transactions and then we will cover OLTP.

Transaction and Transaction System:

A transaction is nothing but an interaction between different users or different systems or between a user and a system.

Transaction systems: Every organization needs some on-line application system to handle their day to day activities. Some examples of transaction systems are: Salary Processing Library, banking, airline etc.

Transaction System

Transaction Properties:

Every transaction follows the ACID property. Learn it like this. This is an important section and government exams choose multiple questions from this section.

ACID

Atomicity: This means a transaction should either completely succeeded or completely fail.

Consistency: Transaction must preserve the database stability. A transaction must transform the database from one consistent state to another

Isolation: This simply means transaction of one user should not interfere with the transactions of some other user in the database.

Durability: Once a transaction is complete means committed, it should be permanently written to the database. This change should be available to all the transactions followed by it.

I hope the ACID properties are clear to you guys. Please let me know if you need more information on this with examples.

Ever wondered how multiple transaction of different users can be processed simultaneously?? If yes check the below magic:

Concurrency: Currency allows two different independent processes to run simultaneously and thus creates parallelism. This is the thing that utilizes the use of fast processing time of computers.

What is Deadlock?

Deadlock is a situation where one transaction is waiting for another transaction to release the resource it needs and vice versa. Therefore, it becomes the case of wait and bound situation and the system halts. Each transaction will be waiting forever for the other to release the resource.

How to prevent Deadlock?

The simple rule to avoid deadlock is if deadlock occurs, one of the participating transaction must be rolled back to allow the other to proceed. So, this way transactions can be performed. There are different kinds of schemes available to decide which transaction should be rolled back.

This decision depends on multiple factors given as following:

  1. The run time of the transaction.
  2. Data already updated by the transaction
  3. Data remaining to be updated by the transaction system

I have tried to cover this section completely friends. Learn these concepts about data science and you will be able to solve each and every question that is related to the data mining section.

In order to master this section, please check my next post of the Previous Year questions of Data Mining section.

Not sure about Computer Networking concepts? Need to score good marks in Computer network section? If yes, do read my next post on Computer Network and Network Topologies. Till then, C yaa friends 🙂

What is a Malicious Program/Malwares? Check the difference between malwares – Virus, Worm, Root Kit, Trojan Horse and Types of Virus

Hi friends, today I am writing about malicious programs – Virus, Root kit, Trojan horse etc and the types of viruses. So, firstly it is very important to know What is malware? It is an important topic for exams like IBPS IT officer, Assistant Manager (IT), SBI IT officer, GIC Officer Scale – I, Computer Teacher, Computer Engineer or any other computer engineer related post. Looking over the importance of this topic, I am explaining this in detail and will also share a questionnaire on it soon. So stay updated with this website and let me know if you want more on this topic. Let’s first understand what Malicious Program is.

What is Malicious Program/Malwares?

Malicious software, which are commonly known as Malwares are a type of software that can harm your computer system. These programs come in different forms for example: viruses, trojans, worms, spyware, adware, root kit, zombie, key loggers etc.

These programs can delete documents, modify or steal the protected data and also add software to your computer programs which are not approved by user.

Hope you get a basic idea of the dangerous nature of these programs. Now, let’s move to the core concepts of this Malicious Programs section so that IT officer post or any computer science post people can answer the questions related to malicious programs.

Malicious Program

Types and Forms of Malicious Programs

Forms of Malicious Programs
Type/Form of Malicious Program Description
Virus It attaches itself to a program and propagates copies of itself to other programs and thus harm the data.
Worm It is a program that propagates copies of itself to other computers basically through Network
Trojan Horse It is a program that contains unexpected additional functionality
Backdoor (Trapdoor) Program that allows unauthorized access to programs and  functionality
Logic Bomb It triggers action when a specific condition occurs
Exploits It is a code specific to a single vulnerability or set of vulnerability
Auto-rooter Malicious hacker tools which are used to break into new machines remotely
Downloader’s Usually downloader’s are sent in an email. It is a program that installs other items on a machine that is under attack.
Key Loggers It captures keystrokes on a compromised system. Think a program is stealing your credentials details during a transaction
Zombie Program activated on an infected machine that is activated to launch attacks on other machines
Root Kit These are Set of hacker tools used after attacker has broken into a computer system and gained root-level access
Flooders Flooders are used to attack networked computer systems with large volume of traffic to carry out a denial of service attach (DoS) attack.
Spammer Programs Spammer programs are also a kind of malicious software. These are used to send large volumes of unwanted emails
Kit (Virus Generators) Kit is a set of tools for generating new viruses automatically

 

I have tried to provide the maximum information that covers most of the questions from Malicious Programs section for government exams.

 

Difference between Computer Virus, Computer Worm, Trojan Horses and Bots

Computer Virus vs Computer Worm :

Computer worms are similar to viruses in the manner that they replicate the functional copies of themselves and can cause the same type of damage. But, still there are some differences in the way these malicious programs cause damage.

In contrast to Viruses, which require the spreading of an infected host file, worms do not require a host file to propagate. Instead, worms are standalone software that do not require any host program or human help to propagate from one computer to another. Now let’s see some basic difference between these malicious programs/malware programs:

 

Virus :

Computer viruses attach a copy of itself to files or programs, infecting each computer it comes across as it spreads. It usually spreads through Emails or executable files. Some viruses are very annoying because they slow down your computer, while others can wreak havoc on your system. Viruses usually modifies files or it may sometimes change the location of a file.

Worms:

Computer Worms also replicate themselves but unlike viruses, these malicious programs do not attach themselves to a program. Instead, these spreads from computer network to network and are extremely dangerous.

These can also damage the servers. Computer worms usually do not infect files. Instead these monetize your computer memory or CPU.

Trojan Horses:

These malicious programs are sneaky ones. Trojan horses hides all sorts of malicious goodies and can harm your computer. These malicious programs may look legitimate software at first glance, but when you install these programs they can delete or modify your files.

Unlike viruses and worms, Trojan horses do not replicate themselves.

Bots:

Bots are a type of malicious programs that may have good intent sometimes. These self-replicating malware is designed to retrieve some sorts of information from the infected system. Bots rarely announce their presence. These malicious programs infect networks in a way that escapes immediate notice.

Life Cycle of Virus/ Phases of Virus:

During its lifetime, a typical virus goes through the following four phases:

  1. Dormant Phase: In this phase, the malicious program Virus is idle. The virus will eventually be activated by some event, such as a date or the presence of another program of file. Not all virus have this stage.
  2. Propagation Phase: In this phase, the virus places an identical copies of itself into other programs or into certain areas on the disk. Each infected area/program in the computer system will now contain a clone of the malicious program Virus.
  3. Triggering Phase: In this phase, the virus is activated to perform the intended function. The triggering phase can be caused by a variety of system events like a specific date or exceeding the disk space to a limit.
  4. Execution Phase: In this phase, the virus perform the intended function. The performed function may be harmless or can damage files or programs of the system.

 

Nature of Viruses:

Viruses are designed in a way to take advantage of the details and weakness of a particular system. These malicious programs are usually specific to a particular hardware platform or a particular operating system in some cases.

Hope the nature of these malicious programs is clear up to this point.

 

Types of Virus:

There are numerous types of viruses but I am sharing the most significant types of Virus here. With the enormous growth of technology and available data, the count of virus types is growing. New viruses are being developed and used. So, here is the list of the most common types of viruses:

Types of Virus

  1. Memory-Resident Virus: It lodges in main memory as part of the resident system program. From that point on, the virus infects every program that executes.
  2. Stealth Virus: This malicious program/malware is explicitly designed to hide itself from any antivirus software. The purpose of the stealth virus is to defeat the virus detection/scan process. To achieve this, the signature of the virus with vary with each replication. The virus may insert superfluous instructions or can also change the order of the independent instruction inside a program.
  3. Parasitic Virus: This is the most common form of virus. A parasitic virus attaches itself to the executable files and replicates. Thus this virus infects other executable files when the infected executable file is executed.
  4. Boot Sector Virus: This virus infects the boot record or the master boot record and thus can prove to be very harmful for the system. Infecting the master boot record, this malicious program spreads when the system is booted with the disk containing the concerned virus.
  5. Polymorphic Virus: This virus mutates itself with every infection, thereby making the detection of the virus impossible.
  6. Metamorphic Virus: This is similar to polymorphic virus, with one difference that it rewrites itself completely with every infection. Hence, these virus change the detection very difficult. The metamorphic virus may change their behavior as well as appearance.

 

Phew… finally I was able to frame all the useful information related to malicious program – Network Security section in this post. Please comment below for any feedback or suggestions. For the previous year IBPS IT Officer/SBI IT Officer/Computer Engineer questions on this section please read my next post here.

 

 

Software Development Vs Software Testing as a Career Option

After spending lot of time for collecting some good content and adding my four years of experience of Software Industry, I have started this blog post. I wonder there must be many college students who are always looking for the difference between software development and software testing to choose as a career option.  Are you also confused for a career option : Software Development vs Software testing? Here we will be checking the tasks you need to follow to choose a career option out of these two.

People should follow this post if they need to switch there job or start their career. So let’s start for career option between Software Development vs Software Testing.

So, here I am giving some points that should be considered while choosing your career option:

Your interest Option

This is the primary task that you need to do. Do self assessment and check what drives you. Software development requires good technical skills. While Testing requires the art of catching bugs and thinking of all the possible outcomes to call out for code flaws of developers :p

So, first thing is Evaluate you interest.

Job Scope as Software Developer:

The hierarchy in software development profile is like : Junior Software Developer -> Senior Software Developer -> Project Manager -> Senior Project Manager

The job profile goes from core technical role to Semi-technical profile. You need to learn project management skills in future. Or you can start your own start-up and cash your skills.

Job Scope as a Software Testing Engineer:

The hierarchy in software testing profile in is like: Junior Testing engineer -> Manual Tester -> Automation Testing Engineer -> Project Manager

Your role can differ if you start your career straight away in automation testing engineer. The job scope changes according to your automation code skills.

Your Skill Set

Make a note of your skill set and the future scope with the options available with your current skills set. For example, if you are good at python, then what kind of profile interests you: A python web developer, python software developer, python web scrappers, python data analyst or python testing engineers (basically the one who writes scripts in python).

What are you good at

Out of your skill set, now do a scoring of your skills. What you are good at. There must be at least one such good skill wherein you can rate yourself 7 or 8 out 10. Then again check, you want coding or analysis stuff in your future. Though in future, you may also need to do coding in testing profile 😀

Your Capability

At the end check, what you can actually do. It is the most important phase, no matter what you want to do, but if you haven’t evaluated yourself or your skills. There can’t be any chances of growth then. So, check capability whether you are good at coding or not. If not go for software testing else go for software development profile.

Three Major Steps:

Listen yourself

Do Self Assessment

Learn and Grow

Look for opportunities

Be happy with what you have but don’t let the hunger for improvement die in you

Smile and live happily 🙂