Oracle DBA Interview Questions and Answers

To make a career in Oracle DBA is not a joke. But you need to be more prepared for the interview questions as the employer wants to make sure that he is doing the right thing by choosing you. In case you have are applying as a fresher, then comprehend these questions well and prepare yourself. In case you have already worked in previous company, then make sure you explain the employer your past experience well enough so that he can ask you question associated with your previous project.


Interview Questions of Oracle DBA are;

Can you please introduce yourself?

In most of the interviews you will get this question. To understand more about yourself will help the employer gain knowledge whether you are that confident individual who can work for their company.

What proper work experience do you hold?

This question is asked to understand your working experience. Try to explain them both relevant and other work experience that you hold. Empathize more on relevant experience as that is what keens the most to the employers.

From where have you persuaded your education?

Usually with this question, the employer tries to understand from which source you have educated yourself. Talking about oracle DBA, certainly a good college or an institute is important. It would be great if you have done it from a well renowned one that will give a push for your chances of cracking the interview.

How clear are you with the concepts of DBA?

This question is asked to understand whether the candidate has got at least the basic knowledge which any project would need with regards to oracle DBA. Try to show up your certifications and degrees that you have received with regards to this subject.

Are you flexible to work in any timing?

Generally employer asks this question because depending on the client requirement you might have to stay as well for long to end the project. At such time it is necessary that you actively show your initiation.

Can you explain us about database?

This is yet another popular question that most of the employer asks. Answer them stating that it is a mechanism at a single point to store and retrieve the data using tables.

What are the well known DBMS that are used frequently for data related issues?

The question is pretty simple. You can name ibm db2, oracle, mysql, sqlLite, sql server and access to name a few that are quite popular.

Please explain the types of storage systems that are available and which is the one used by oracle?

Storage system comes in two types namely Hierarchical Storage Management System (HSM) and Relational Database Management System (RDBMS). Usually, RDBMS model is frequently used by oracle.

What are the types of Join methods that are used frequently?

Join methods are available in 3 types called Nested loop join, Merge Join and Hash join. Each type of join holds a special feature and is said to be extremely important in Oracle DBA.

Name the components of logical data model that are used on a large scale?

Entity stores the information and attributes displays the information of the entity. Record is the collect of necessary properties and domain is the set of value for a certain attribute. Other than this, there is also an entity called relation which shows the link between two entities.

What is the Difference between Logical and Physical data model?

The name itself suggests what the core difference is. Logical data is the representation of the logical subjects like entities where as physical data is the representation of the physical objects like constraints.

What is normalization?

This is quite commonly asked for the fact that in most of the projects it is required. It is a process where fields and tables of a relational database are organized well. This reduces the dependency and saves ample of storage as well.

What are the types of normalization?

Normalization is categorized in six types called First Normal Form which has got atomic values, Second Normal Form which is completely depend on primary key. Then comes the Third Normal Form, Boyce Codd Normal Form and fourth and fifth normal form.

Can you differentiate between Oracle service and oracle SID name?

SID is a unique name gives to recognize the different identity present in the database. Service is TNS alias name and can be similar or different than SID.

Name the kernel parameter that affects the installation of oracle?

SHMMNI and SHMMAX are the respective names which needs to be set before the process of installation of oracle begins.

Please explain the bind variables?

If you use “bind variable in SQL”, the queries can easily be cached by Oracle in only one time. Thus the harsh parse every time is avoided and you can save ample of money on different lock and latch sources.

Can you give the right coding to check if application 11i System is Autoconfig enabled?

For this you simply need to type under $AD_TOP/bin check. This will help you check the file and if it is still present, then you can use contextfile=<CONTEXT> show=enabled. If the file is missing then you can look for other option of configuration  with entry like APPL_TOP. For this however the system needs to be Autoconfig enabled.

Can you explain the “difference between data block/segment/extent?”

All these things are connected to each other out of which data block is a very smallest and simplest one used for storing the database object. Then once the grouping of data blocks is done, it becomes extents and when entire extents are taken by the object then it is said to be the segment of the DB object.

Please explain us about Oracle Home Inventory?

This type of inventory is representing inside the home of oracle. It only contains the data which is related to a particular Oracle home. The file which is located in a particular location $ORACLE_HOME/inventory is only located.

What are the files and folders in the home inventory?

Generally it contains three important files and folders called Home Properties File, Components File and Other Folders.