Year 2011 was a year of learning and opportunity for me. My recent book, SQL Server Interview Questions and Answers, has received such overwhelming love and support from all of you. While writing the book, I had two simple goals: (1) Master the Basics and (2) Ignite Learning. There was a constant request from the Community to take the learning of these books to the next level. Here is an article which discusses the Author’s Perspective.
Beyond Relational has come up with a very interesting concept – they have converted a few of the questions from my book into the SQL Quiz. The quiz is indeed focused on my two goals. In addition, it’s going to put the learning of the book to a higher stage. Looking at this novel concept, Vinod Kumar (Co-author) and I have decided to help every participant and reader by giving a few hints and suggestions to solve the quiz.
Reporting and analytics cannot be achieved without a very good data model at the background. And using Analysis services for reporting requirement is always something very common architecture to this. But getting data from relational engine and keeping data for analysis up to date is the challenge. Having these in mind, what is the concept of Slowly Changing Dimension? And what is a Hybrid Slowly Changing Dimension?
Modeling can be a tricky activity. The way to load a SCD can be achieved interestingly via the SSIS route. Though the basics of SCD can be a larger discussion, tell us more about a thing or two on what you have learned so far in loading SCD.
Let us talk about a product in a shop. Let us assume the product is newly launched. The price of the product is very high and it is put in the ‘newly arrived products’ section. After. a while the book becomes best seller and it is moved to the ‘best seller’ section. As time progresses, the rate of sales of the book declines, leading to it getting moved off the best sellers’ group to the ‘regular items’ section. Eventually, the same book is moved to the bargain section and with a very low price value. Well, this product life process is slow changing. If we consider the price of the book as well as the duration it spent in particular section, it is very much comparable to a slowly changing dimension in SQL Server. Now that you know this simple comparison, the quiz should be easier for you.
SQL Server Interview Questions and Answers ISBN: 1466405643 Page#179-180
Note: SQL Quiz, winners and prizes are administrated by Beyond Relational. The goal of this blog post is to provide additional learning pointers only.
Reference: Pinal Dave (http://blog.sqlauthority.com)