Tuesday, 19 May 2015
Monday, 18 May 2015
Who am I ?. The video about who you are?
This film deals with Journey that takes you to the eternal truth, for
which from time immemorial, people have been trying to explore and
discover a simple truth to understand the self, Karma & Rajyoga
Meditation.
Tamil Video
English Video
What is Database?
A database is a systematic collection of data. Databases support storage and manipulation of data. Databases make data management easy. Let's discuss few examples.
An online telephone directory would definitely use database to store data pertaining to people, phone numbers, other contact details, etc.
Your electricity service provider is obviously using a database to manage billing , client related issues, to handle fault data, etc.
Let's also consider the facebook. It needs to store, manipulate and present data related to members, their friends, member activities, messages, advertisements and lot more.
We can provide countless number of examples for usage of databases .
Database Management Systems are not a new concept and as such had been first implemented in 1960s. Charles Bachmen's Integrated Data Store(IDS) is said to be the first DBMS in history. With time database technologies evolved a lot while usage and expected functionalities of databases have been increased immensely.
There are 4 major types of DBMS. Let's look into them in detail.
1.What is Structured Query language (SOL)
Structured Query language (SQL) pronounced as "S-Q-L" or sometimes as "See-Quel"is actually the standard language for dealing with Relational Databases. SQL can be effectively used to insert, search, update, delete database records. That doesn't mean SQL cannot do things beyond that. In fact it can do lot of things including, but not limited to ,optimizing and maintenance of databases. Relational databases like MySQL, Oracle, Ms SQL server, Sybase, etc uses SQL ! SQL syntaxes used in these databases are almost similar, except the fact that some are using few different syntaxes and even proprietary SQL syntaxes.
Concept of NoSQL databases grew with internet giants such as Google, Facebook, Amazon etc who deal with gigantic volumes of data.When you use relational database for massive volumes of data , the system starts getting slow in terms of response time. To overcome this , we could of course "scale up" our systems by upgrading our existing hardware. The alternative to the above problem would be to distribute our database load on multiple hosts as the load increases. This is known as "scaling out".
NOSQL database are non-relational databases that scale out better than relational databases and are designed with web applications in mind. They do not use SQL to query the data and do not follow strict schemas like relational models.With NoSQL, ACID (Atomicity, Consistency, Isolation, Durability) features are not guaranteed always.
Relational databases have the following advantages over NOSQL databases;
An online telephone directory would definitely use database to store data pertaining to people, phone numbers, other contact details, etc.
Your electricity service provider is obviously using a database to manage billing , client related issues, to handle fault data, etc.
Let's also consider the facebook. It needs to store, manipulate and present data related to members, their friends, member activities, messages, advertisements and lot more.
We can provide countless number of examples for usage of databases .
What is a Database Management System (DBMS)
Database Management System (DBMS) is a collection of programs which enables its users to access database, manipulate data, reporting / representation of data . It also helps to control access to the database.Database Management Systems are not a new concept and as such had been first implemented in 1960s. Charles Bachmen's Integrated Data Store(IDS) is said to be the first DBMS in history. With time database technologies evolved a lot while usage and expected functionalities of databases have been increased immensely.
Types of DBMS
Let's see how the DBMS family got evolved with the time. Following diagram shows the evolution of DBMS categories.There are 4 major types of DBMS. Let's look into them in detail.
- Hierarchical - this type of DBMS employs the "parent-child" relationship of storing data. This type of DBMS is rarely used nowadays. Its structure is like a tree with nodes representing records and branches representing fields. The windows registry used in Windows XP is an example of a hierarchical database. Configuration settings are stored as tree structures with nodes.
- Network DBMS - this type of DBMS supports many-to many relations. This usually results in complex database structures. RDM Server is an example of a database management system that implements the network model.
- Relational DBMS - this type of DBMS defines database relationships in form of tables, also known as relations. Unlike network DBMS, RDBMS does not support many to many relationships.Relational DBMS usually have pre-defined data types that they can support. This is the most popular DBMS type in the market. Examples of relational database management systems include MySQL, Oracle, and Microsoft SQL Server.
- Object Oriented Relation DBMS - this type supports storage of new data types. The data to be stored is in form of objects. The objects to be stored in the database have attributes (i.e. gender, ager) and methods that define what to do with the data. PostgreSQL is an example of an object oriented relational DBMS.
1.What is Structured Query language (SOL)
Structured Query language (SQL) pronounced as "S-Q-L" or sometimes as "See-Quel"is actually the standard language for dealing with Relational Databases. SQL can be effectively used to insert, search, update, delete database records. That doesn't mean SQL cannot do things beyond that. In fact it can do lot of things including, but not limited to ,optimizing and maintenance of databases. Relational databases like MySQL, Oracle, Ms SQL server, Sybase, etc uses SQL ! SQL syntaxes used in these databases are almost similar, except the fact that some are using few different syntaxes and even proprietary SQL syntaxes.
What is NoSQL ?
NoSQL is an upcoming category of Database Management Systems..Its main characteristic is its non-adherence to Relational Database Concepts. NOSQL means "Not only SQL".
Concept of NoSQL databases grew with internet giants such as Google, Facebook, Amazon etc who deal with gigantic volumes of data.When you use relational database for massive volumes of data , the system starts getting slow in terms of response time. To overcome this , we could of course "scale up" our systems by upgrading our existing hardware. The alternative to the above problem would be to distribute our database load on multiple hosts as the load increases. This is known as "scaling out".
NOSQL database are non-relational databases that scale out better than relational databases and are designed with web applications in mind. They do not use SQL to query the data and do not follow strict schemas like relational models.With NoSQL, ACID (Atomicity, Consistency, Isolation, Durability) features are not guaranteed always.
Relational databases have the following advantages over NOSQL databases;
- SQL(relational) databases have a mature data storage and management model . This is crucial for enterprise users.
- SQL databases support the notion of views which allow users to only see data that they are authorized to view. The data that they are not authorized to see is kept hidden from them.
- SQL databases support stored procedures which allow database developers to implement part of the business logic into the database.
- SQL databases have better security models compared to NoSQL databases.
What is Normalization?
Normalization is a database design technique which organizes tables in a manner that reduces redundancy and dependency of data.
It divides larger tables to smaller tables and link them using relationships.
The inventor of the relational model Edgar Codd proposed the theory of normalization with the introduction of First Normal Form and he continued to extend theory with Second and Third Normal Form. Later he joined with Raymond F. Boyce to develop the theory of Boyce-Codd Normal Form.
Theory of Normalization is still being developed further. For example there are discussions even on 6th Normal Form. But in most practical applications normalization achieves its best in 3rd Normal Form. The evolution of Normalization theories is illustrated below-
Let's learn Normalization with practical example -
Assume a video library maintains a database of movies rented out. Without any normalization all information is stored in one table as shown below.
Here you see Movies Rented column has multiple values.
Now let's move in to 1st Normal Form
1NF Rules
- Each table cell should contain single value.
- Each record needs to be unique.
Before we proceed lets understand a few things --
Note: Columns in a table that are NOT used to uniquely identify a record are called non-key columns.
What is a primary Key?
What is a KEY ?
A KEY is a value used to uniquely identify a record in a table. A KEY could be a single column or combination of multiple columnsNote: Columns in a table that are NOT used to uniquely identify a record are called non-key columns.
What is a primary Key?
A primary is a single column values used to uniquely identify a database record. It has following attributes
|
What is a composite Key?
A composite key is a primary key composed of multiple columns used to identify a record uniquelyIn our database , we have two people with the same name Robert Phil but they live at different places.
Hence we require both Full Name and Address to uniquely identify a record. This is a composite key.
Let's move into 2NF
2NF Rules
- Rule 1- Be in 1NF
- Rule 2- Single Column Primary Key
We have introduced a new column called Membership_id which is the primary key for table 1. Records can be uniquely identified in Table 1 using membership id
Introducing Foreign Key!
In Table 2, Membership_ID is the foreign KeyForeign Key references primary key of another Table!It helps connect your Tables
|
Suppose an idiot inserts a record in Table B such as
You will only be able to insert values into your foreign key that exist in the unique key in the parent table. This helps in referential integrity.
The above problem can be overcome by declaring membership id from Table2 as foreign key of membership id from Table1
Now , if somebody tries to insert a value in the membership id field that does not exist in the parent table , an error will be shown!
What is a transitive functional dependencies?
A transitive functional dependency is when changing a non-key column , might cause any of the other non-key columns to changeConsider the table 1. Changing the non-key column Full Name , may change Salutation.
Let's move into 3NF
3NF Rules
- Rule 1- Be in 2NF
- Rule 2- Has no transitive functional dependencies
We have again divided our tables and created a new table which stores Salutations.
There are no transitive functional dependencies and hence our table is in 3NF
In Table 3 Salutation ID is primary key and in Table 1 Salutation ID is foreign to primary key in Table 3
Now our little example is in a level that cannot further be decomposed to attain higher forms of normalization. In fact it is already in higher normalization forms. Separate efforts for moving in to next levels of normalization are normally needed in complex databases. However we will be discussing about next levels of normalizations in brief in the following.
Boyce-Codd Normal Form (BCNF)
There are no transitive functional dependencies and hence our table is in 3NF
In Table 3 Salutation ID is primary key and in Table 1 Salutation ID is foreign to primary key in Table 3
Now our little example is in a level that cannot further be decomposed to attain higher forms of normalization. In fact it is already in higher normalization forms. Separate efforts for moving in to next levels of normalization are normally needed in complex databases. However we will be discussing about next levels of normalizations in brief in the following.
Boyce-Codd Normal Form (BCNF)
Even when a database is in 3rd Normal Form, still there would be anomalies resulted if it has more than one Candidate Key.
Sometimes is BCNF is also referred as 3.5 Normal Form.
Sometimes is BCNF is also referred as 3.5 Normal Form.
4th Normal Form
If no database table instance contains two or more, independent and multivalued data describing the relevant entity , then it is in 4th Normal Form.5th Normal Form
A table is in 5th Normal Form only if it is in 4NF and it cannot be decomposed in to any number of smaller tables without loss of data.6th Normal Form
6th Normal Form is not standardized yet however it is being discussed by database experts for some time. Hopefully we would have clear standardized definition for 6th Normal Form in near future.Sunday, 17 May 2015
Inspiration from geniuses
1. Albert Einstein » Physicist
Best known for the General Theory of Relativity.
Most of us take Einstein’s name as synonymous with genius, but he didn’t always show such promise. Einstein did not speak until he was four and did not read until he was seven, causing his teachers and parents to think he was mentally handicapped, slow and anti-social.
Eventually, he was expelled from school and was refused admittance to the Zurich Polytechnic School. It might have taken him a bit longer, but most people would agree that he caught on pretty well in the end, winning the Nobel Prize and changing the face of modern physics.
2. Walt Disney » Business Man
Founder of The Walt Disney Company.
Today Disney rakes in billions from merchandise, movies and theme parks around the world, but Walt Disney himself had a bit of a rough start. He was fired by a newspaper editor because, “he lacked imagination and had no good ideas.”
After that, Disney started a number of businesses that didn’t last too long and ended with bankruptcy and failure. He kept plugging along, however, and eventually found a recipe for success that worked.
3. Isaac Newton » Scientist
Best known for: Universal gravitation, Newton’s method,
Newtonian mechanics, Optics, Infinitesimal calculus.
Newton was undoubtedly a genius when it came to math, but he had some failings early on. He never did particularly well in school and when put in charge of running the family farm, he failed miserably, so poorly in fact that an uncle took charge and sent him off to Cambridge where he finally blossomed into the scholar we know today.
4. Thomas Edison » Inventor and Businessman
Best known for Electric Light Bulb.
In his early years, teachers told Edison he was “too stupid to learn anything.”
Work was no better, as he was fired from his first two jobs for not being productive enough. Even as an inventor, Edison made 1,000 unsuccessful attempts at inventing the light bulb. Of course, all those unsuccessful attempts finally resulted in the design that worked.
5. Henry Ford » Business Man
Founder of Ford Motor.
While Ford is today known for his innovative assembly line and American-made cars, he wasn’t an instant success. In fact, his early businesses failed and left him broke five times before he founded the successful Ford Motor Company.
6. Soichiro Honda » Business Man
Founder of Honda Motor.
The billion-dollar business that is Honda began with a series of failures and fortunate turns of luck. Honda was turned down by Toyota Motor Corporation for a job after interviewing for a job as an engineer, leaving him jobless for quite some time.
He started making scooters of his own at home, and spurred on by his neighbors, finally started his own business.
7. Akio Morita » Business Man
Founder of Sony Corporation.
You may not have heard of Morita but you’ve undoubtedly heard of his company, Sony.
Sony’s first product was a rice cooker that unfortunately didn’t cook rice so much as burn it, selling less than 100 units. This first setback didn’t stop Morita and his partners as they pushed forward to create a multi-billion dollar company.
8. Orville and Wilbur Wright (Wright Brothers) » Airplane Inventors
Education: Completed High School.
These brothers battled depression and family illness before starting the bicycle shop that would lead them to experimenting with flight.
After numerous attempts at creating flying machines, several years of hard work, and tons of failed prototypes, the brothers finally created a plane that could get airborne and stay there.
9. Winston Churchill » UK Politician
This Nobel Prize-winning, twice-elected Prime Minster of the United Kingdom wasn’t always as well regarded as he is today.
Churchill struggled in school and failed the sixth grade. After school he faced many years of political failures, as he was defeated in every election for public office until he finally became the Prime Minister at the ripe old age of 62.
10. Abraham Lincoln » US Politician
While today he is remembered as one of the greatest leaders of our nation, Lincoln’s life wasn’t so easy. In his youth he went to war a captain and returned a private (if you’re not familiar with military ranks, just know that private is as low as it goes.)
Lincoln didn’t stop failing there, however. He started numerous failed business and was defeated in numerous runs he made for public office.
11. Vincent Van Gogh » Artist
During his lifetime, Van Gogh sold only one painting, and this was to a friend and only for a very small amount of money.
While Van Gogh was never a success during his life, he plugged on with painting, sometimes starving to complete his over 800 known works.
12. Michael Jordan » Basketball Player
Most people wouldn’t believe that the man often lauded as the best basketball player of all time was actually cut from his high school basketball team.
Luckily, Jordan didn’t let this setback stop him from playing the game and he has stated, “I have missed more than 9,000 shots in my career. I have lost almost 300 games. On 26 occasions I have been entrusted to take the game winning shot, and I missed. I have failed over and over and over again in my life. And that is why I succeed.”
Source from : http://academictips.org/blogs/inspiration-from-top-geniuses/
What is Business Intelligence?
Business Ingelligence (BI) - technology infrastructure for gaining maximum information from available data for the purpose of improving business processes. Typical BI infrastructure components are as follows: software solution for gathering, cleansing, integrating, analyzing and sharing data. Business Intelligence produces analysis and provides believable information to help making effective and high quality business decisions.
The most common kinds of Business Intelligence systems are:
Business Intelligence systems based on Data Warehouse technology. A Data Warehouse(DW) gathers information from a wide range of company's operational systems, Business Intelligence systems based on it. Data loaded to DW is usually good integrated and cleaned that allows to produce credible information which reflected so called 'one version of the true'.
List of BI tools in the market :
- SAP BusinessObjects: a complete BI platform
- IBM Cognos Series 10: strong in analytics
- JasperSoft: open source, now TIBCO
- Microsoft BI tools: a complete BI platform
- MicroStrategy: strong in reporting & performance
- Oracle BI (OBIEE): a complete BI platform
- Oracle Hyperion System: tool for consolidation
- Pentaho BI: open source, now HDS
- Yellowfin BI: strong in dashboards
- Qlik: strong in Data Discovery
- SAP NetWeaver BW: data warehouse + cubes
- SAS BI: very strong in analytics
- Style Intelligence: a niche player
- Tableau Software: strong in Data Visualization
- WebFOCUS: a complete BI platform
- BizzScore: strong in performance management
- Board: strong in performance management
- Birst: a complete BI platform in the cloud
Flipkart Marketing strategy
Flipkart digital marketing
It’s being touted as India’s answer to Amazon. Founded by Sachin Bansal and Binny Bansal (not related to each other) in Oct 2007, Flipkart has catapulted to one of India’s most popular e-commerce sites and undoubtedly as the most popular online destination for books within a short span of three years. With expected revenues of Rs. 75 crores this FY, Flipkart plans to generate a whopping Rs. 4,500 crores by FY2015. Now that’s pretty impressive for any business.Flipkart’s initial success can be pegged down to the experience of its founders, both of whom had worked with Amazon. They also successfully used word of mouth marketing and social media to get word out. But there are literally millions of retail websites. And not many have achieved even a fraction of the attention that Flipkart has. So what is it that makes Flipkart stand out? For one, they offer a huge range of titles (more than 7 million) which really sets them apart from the rest of the crowd.
But is simply offering so many titles enough? I don’t think so. I mean, how difficult is it for someone with deep pockets to simply replicate this? Not very. In fact, the Bansals started their venture with just Rs. 5 lakhs. So what does Flipkart have that makes its model so robust? An amazingly well-oiled warehousing and delivery system. This ensures that deliveries occur within promised times all over India. And with a business volume of nearly 2 lakh books every year, one can imagine how important logistics is to this business.
So what’s my take on Flipkart? I personally didn’t like the website interface so much. And this one’s supposed to be a newer one. It didn’t inspire me at all. And they still haven’t turned a profit yet. But on the positive side, they have the scope and the scale. They are adding new product lines such as movies, music, games, cameras and computers. They are coming up with creative ads and improving operations. They have just received another round of funding. All in all, there’s no doubt that Flipkart has tremendous potential.
Featured Image Source: http://www.flickr.com/photos/nadircruise/5489567292/
What is Big Data?
In the process of discovering and determining these insights, large
complex sets of data are generated that then must be managed, analyzed
and manipulated by skilled professionals. The compilation of this large
collection of data is collectively known as big data.
Most professionals in the industry consider multiple terabytes or
petabytes to be the current big data benchmark. Others, however, are
hesitant to commit to a specific quantity, as the rapid pace of
technological development may render today’s concept of big as
tomorrow’s normal. Still others will define big data relative to its
context. In other words, big data is a subjective label attached to
situations in which human and technical infrastructures are unable to
keep pace with a company’s data needs.
In addition to volume, the big data label also includes data variety and velocity making up the three V’s of big data – volume, variety and velocity. Variety references the different types of structured and unstructured data that organizations can collect, such as transaction-level data, video, and audio, or text and log files. Velocity is an indication of how quickly the data can be made available for analysis.
In addition to the three V’s, some add a fourth to the big data definition. Veracity is an indication of data integrity and the ability for an organization to trust the data and be able to confidently use it to make crucial decisions.
Big data can lead to improvements in overall operations by giving organizations greater visibility into operational issues. Operational insights might depend on machine data, which can include anything from computers to sensors or meters to GPS devices. Big data provides unprecedented insight on customers’ decision-making processes by allowing companies to track and analyze shopping patterns, recommendations, purchasing behavior and other drivers that are known to influence sales.
So, how big is big data?
The Three – and Sometimes Four – V’s of Big Data
Though the word big implies such, big data isn’t simply defined by volume, it’s about complexity. Many small datasets that are considered big data do not consume much physical space but are particularly complex in nature. At the same time, large datasets that require significant physical space may not be complex enough to be considered big data.In addition to volume, the big data label also includes data variety and velocity making up the three V’s of big data – volume, variety and velocity. Variety references the different types of structured and unstructured data that organizations can collect, such as transaction-level data, video, and audio, or text and log files. Velocity is an indication of how quickly the data can be made available for analysis.
In addition to the three V’s, some add a fourth to the big data definition. Veracity is an indication of data integrity and the ability for an organization to trust the data and be able to confidently use it to make crucial decisions.
Understanding the Big Picture of Big Data
To gain a better perspective on how much data is being generated and managed by big data systems, consider the following noteworthy facts:- According to IBM, users create 2.5 quintillion bytes of data every day. In practical terms, this means that 90% of the data in the world today has been created in the last two years alone
- Walmart controls more than 1 million customer transactions every hour, which are then transferred into a database working with over 2.5 petabytes of information
- According to FICO, the credit card fraud system currently in place helps protect over two billion accounts all over the globe
- Facebook currently holds more than 45 billion photos in its user database, a number that is growing daily
- The human genome can now be decoded in less than one week, a feat which originally took ten years to complete
Uses of Big Data
As stated earlier, organizations are increasingly turning to big data to discover new ways to improve decision-making, opportunities, and overall performance. For example, big data can be harnessed to address the challenges that arise when information that is dispersed across several different systems that are not interconnected by a central system. By aggregating data across systems, big data can help improve decision-making capability. It also can augment data warehouse solutions by serving as a buffer to process new data for inclusion in the data warehouse or to remove infrequently accessed or aged data.Big data can lead to improvements in overall operations by giving organizations greater visibility into operational issues. Operational insights might depend on machine data, which can include anything from computers to sensors or meters to GPS devices. Big data provides unprecedented insight on customers’ decision-making processes by allowing companies to track and analyze shopping patterns, recommendations, purchasing behavior and other drivers that are known to influence sales.
Big Data - Videos
Friday, 15 May 2015
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