Member-only story
The T of ETL: Transform
Easiest and most beginner-friendly introduction to Transformation in ETL
Written by Rashmi Metri
Data has always been the hero! I say not just the heroine, but everything revolves around data. Agree? Data is being generated from time immemorial. Storing it is also not something ancient. Data is stored in books, receipts, papers, ledgers, databases, data warehouses, etc., and a lot of other storage devices and forms. But, till recent years, this stored data just stayed behind the curtains, it did not come into the limelight.
Now think of your city library, there are umpteen books. Now, the librarian has all the data regarding the books. The author, publisher, the day the book was brought to the library, the different records of the number of people who have issued the book, and so on. Every day, a lot of books would be borrowed and a lot would be returned. So, every day a lot of rows of data were added and perhaps modified too. Month on month, year on year, data just kept added to the database.
One day, you(an avid book reader), request the librarian for the list of all the books you have borrowed, so what is to be done — Filter by your name. Your request to provide the book names you borrowed month-wise for the whole of last year. But she realizes the date is stored in…
