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SQL Server, DBA interview questions Database
A site visitor writes: Here are some SQL Server DBA/Developer interview questions I faced myself personally and/or heard from people. I will try to answer these questions briefly here, but be advised that these answers may not be complete and it will be better for you to go through text books, books online and other resources on the net.
Before you go for the interview, be prepared to explain the database design of one of your latest projects. Don’t be surprised if the interviewer asks you to draw ER diagrams.
Well, here are some questions for you. Hope this helps you prepare for your interview. Wish you all the best in your job hunt! Feel free to email me ‘interview questions’ that you’ve faced.
Questions are categorized under the following sections, for your convenience:
Database design (8 questions)
SQL Server architecture (12 questions)
Database administration (13 questions)
Database programming (10 questions)
Database design

What is normalization? Explain different levels of normalization?
Check out the article Q100139 from Microsoft knowledge base and of course, there’s much more information available in the net. It’ll be a good idea to get a hold of any RDBMS fundamentals text book, especially the one by C. J. Date. Most of the times, it will be okay if you can explain till third normal form.
What is denormalization and when would you go for it?
As the name indicates, denormalization is the reverse process of normalization. It’s the controlled introduction of redundancy in to the database design. It helps improve the query performance as the number of joins could be reduced.
How do you implement one-to-one, one-to-many and many-to-many relationships while designing tables?
One-to-One relationship can be implemented as a single table and rarely as two tables with primary and foreign key relationships. One-to-Many relationships are implemented by splitting the data into two tables with primary key and foreign key relationships. Many-to-Many relationships are implemented using a junction table with the keys from both the tables forming the composite primary key of the junction table. It will be a good idea to read up a database designing fundamentals text book.