Data science interview questions:
Data can be classified into 3 types:
1024 bytes= 1 KB
The real challenge starts when we move to petabyte of data.
Big Data has to do with petabyte and above.
Sources of Big Data:
Computer generated data: minimal human interaction. Gaming servers, web servers.
Hand generated data : Day to day activities like going to bank. Facebook, LinkedIn, Twitter. Everything is included the mouse click.
Big data: Data coming in from all sources. It can be human generated or computer generated.
New York stock exchange products 4-5TB of data per day. Internet stores 18.5 petabyte of data on a day. 7 billion cell phones store 60-80 gigabytes of data every second: text, call is analysed for some type of analysis.
Data from YouTube: 40-50 hours of video uploaded more than few terabyte per minute.
Twitter: 12 terabyte tweet everyday.
Yahoo: 60 petabyte per day.
eBay: 40 petabyte per day.
Data Centric 