Hello , once you are ready with the 'HR' type of questions , (you can take a look at some of the questions and answers at HR questions) it is obviously important for getting ready for the technical and one of the subjects , and DBMS is one of the leading ones from both the parties. So I pen down few DBMS questions, this are all indicative ones , just to give you an idea on the depth and breadth. Normalization, Transactions , SQL and Indexing , I have seen to be all time favorites.
Feel free to give your comments , post answers , more questions , any other feedback.
Imagining you guyz are reading this because of your impending campus , read smartly , fine balancing with enjoying life , work on a plan and you will be partying in time :)
DBMS :
General
- What is OLAP and OLTP?
- What are the advantages of DBMS over file system? ( Do not forget key ones like transaction , normalization, indexing , locking , logging etc. )
- Why RDBMS called RDBMS ? Stress on the relational part.
- Draw an ER Diagram for the project you did ?
- .What is the degree of a relationship? Does relationships always needs a table ?
- How do you achieve generalization and specialization in an ER?
Normalization
- Why do we normalize?
- What are the different anomalies?
- Why do we denormalize ?
- Give an example of a table , which is not in 3 NF , explain diffrent anomalies in that context , tell how you will make it normalized
Transaction
- What is a transaction?
- What is ACID property? Explain each one with example.
- How the durability property is implemented ?
- How do you implement a transaction from a programming language like C# or java?
- Can a transaction be partially committed ?
- What is locking , what is two phase locking ?
- What is seralizability ?
Integrity
- What are different type of constraints ?
- What is primary key , foreign key , candidate key ?
- What is unique , Check constrains
- Difference between a primary key and unique constraint ?
- Is it possible to create a table with out a primary key ?
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Indexing:
- Why do we use index?
- What are the overheads of index?
- What is the difference between clustered index and a non-clustered index ?
- What is the difference between B Tree and B+ Tree
- Another way of asking the same question , what are the diffrent data structures that are used
SQL:
- What is difference between a function and stored procedure ?
- What is cursor ? What are the different types of cursor in oracle ?
- What are the different indices that oracle support?’ ( Special focus on bitmap indices)
- What is the difference on where and having clause ?
- Questions on NULL
- What is the difference between char data type and varchar data type?
- What is a view? What is materialised view? Why they are used?What are different types of joins , what is difference between a Cartesian product and a full outer join ( Practise this with few examples )
- What is the function of UNION ? Is it different from UNION ALL?
- What is DDL and DML, how truncate is different from Delete
- Where will you use trigger , what are the different types of trigger ?
- Why do we create packages ?
- How do we handle exceptions?
- What is the role of dual ?
- If two tables have PK - FK relationship and you want when the PK gets deleted , the FK entries also gets deleted , how do you do that ?
- Why and how do you create sequences?
- How can you delete dupicate data from a table ?
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