Top Oracle DBA Interview Questions and Answers

Introduction

Restless nights, sweat-soaked palms and feet, agitation, insecurity and much more are some of the things that every individual experience before their interview sessions. All our psyche and body is essentially focussed on those urgent minutes of our lives. All we need that time is only some supernatural occurrence that can instill the much-needed confidence in us. We are here with one truly miracle blog for you today. By the method for this blog, we will make you mindful of the normal questions that are asked in the interview sessions relating to Oracle Database Administrator.

Here is a very good and comprehensive list of a couple of very frequently asked Oracle Database Administrators inquiries alongside their answers. This list has been dexterously prepared by our industry expert panelists selected from the worldwide businesses who additionally prepare students for the Oracle DBA courses to give you a good idea of the sort of questions that might be asked from you in the interview. An Oracle database is an accumulation of data usually regarded as a unit. The reason for a database is to store and recover related data. A database server is a wayof taking care of the issues of data administration.

As a rule, a server dependably deals with a lot of information in a multiuser domain so that a significant number of clients can simultaneously get access to similar information. This is a refined process that conveys a superior performance drive. A database server likewise counteracts unapproved access cases and gives proficient answers for failure recuperation.

Oracle Interview Questions

1. What is Oracle?
2. What is an Oracle Database?
3. Explain the Common Oracle DBA Responsibilities?
4. Explain the meaning of SQL?
5. Explain the meaning of Database Management System.
6. What are different Oracle database objects?
7. What are the benefits of ORDBMS?
8. What is an Oracle index?
9. Explain the Oracle Grid Architecture?
10. How does the role of an Oracle DBA role differ from that of an Oracle Developer?
11. What are the types of storage systems accessible in Oracle?
12. Highlight a few ways to join methods in Oracle Database
13. Explain the mechanisms of logical data model?
14. What is the difference between Logical and Physical data model?
15. Explain the meaning of query?
16. Explain in detail the function of ‘SELECT’ command in Oracle database?
17. What is normalization in Oracle?
18. What are the different forms of normalization?
19. What are the types of disk components available in Oracle?
20. Elucidate the difference between a cluster and a grid?

Oracle Database Administrator Interview questions and answers

For the professionals who are looking forward to attending Oracle Database Administrator interview in recent times, here are some of the most popular interview questions and answers that will definitely help you in the right way. Over here, we have included the top frequently asked questions with answers to help the freshers as well as the experienced professionals in the field.

Oracle Database Administrator Interview questions and answers for Freshers

Q1). What is Oracle?

Oracle is a company that provides a database server, which in turn manages data in a very organized and structured way. It permits its users to store and download the related data in an environment where many users can at the same time access the same data.

Q2). What is an Oracle Database?

Oracle provides you with software to create and run the Oracle database. The database comprises of physical and logical apparatuses and algorithms in which things like the system, user, and control information is stored. This software which manages the database is called the Oracle database server. The software that runs Oracle along with the physical database is what we call as the Oracle database system.

Q3). Explain the Common Oracle DBA Responsibilities.

As an Oracle DBA, you are expected to perform the following tasks:

• Connecting Oracle software
• Generating Oracle databases
• Accomplishment upgrades of the database and application to new announcement levels
• Preliminary up and conclusion down the database
• Handling the database’s storage assemblies
• Handling users and safety
• Supervision plan objects, such as tables, indexes, and opinions
• Making database backups and performing recovery when necessary
• Proactively supervision of the database’s well-being and taking precautionary or counteractive achievements as essential
• Supervising and tuning presentation. In a minor to midsize database setting, you might be the solitary individual accomplishing these tasks. In great enterprise settings, the job is often alienated amid numerous DBAs, each with their individual area of the subject, such as the database safety administrator or database tuning practiced.

Q4). Explain the meaning of SQL.

Structured Query Language is the elementary method of asking a database server to exchange to you. Whether that is in the setting of asking it a query, giving it responses to queries it is asking you, or informing responses that have previously been stored in the database. The art of requesting the correct question is serious to receiving back the correct data you want, which is extremely valued when dealing with databases, as it is extremely easy to accept far more information than you distinguish what to do with, or nothing at all together.

Q5). Explain the meaning of a Database Management System.

A Database Management System, or DBMS, is fundamentally the request that levers the heavy elating amid you (the user), and the rare information. The database itself is merely that — the database; it cannot modify its own information any extra than the regular individual can re-arrange their inherited code. The DBMS is what you are speaking to when you are enquiring the queries. It is what aspects of your query, reflect about it for a while, drives to the database, prefers up the information, arrows it back to you, and requests you to come again.

Q6). What are the different Oracle database objects?

Here is a list of different Oracle database objects-

• Tables
• Views
• Indexes
• Synonyms
• Sequences
• Tablespaces

Q7). What are the benefits of ORDBMS?

The benefits are that the objects can be easily stored in the database. The language of the DBMS can be swiftly integrated with the said object-oriented programming language. The language of the database may even be exactly the same as that which is used in the application, which saves the programmer from having two representations of his objects.

Q8). What is an Oracle index?

An Oracle index is an optional formation connected with a table so that it can have direct access to rows, which can be easily created to enhance the performance of the data retrieval process. The best part is that the index can be shaped up for one or more columns of a table.

Q9). Explain the Oracle Grid Architecture.

The Oracle grid architecture pools in a large number of things such as the servers, storage, and networks into anelastic, on-demand computing kind of a resource for the purpose of an enterprise’s computing needs.

Q10). How does the role of an Oracle DBA role differ from that of an Oracle Developer?

An Oracle developer is mostly responsible for developing the backend apps. Their job is to do data modeling according to the business rules. They are expected to design tables, create various indexes and many another type of constraints. They are expected to know languages such as SQL and PL/SQL. They develop procedures using these languages. However, the Oracle developers are not per se expected to administer the Oracle database software itself.

Oracle Database Administrator Interview questions and answers for Experienced

Q11). What are the types of storage systems accessible in Oracle?

The following types of storing systems are accessible in Oracle:

• One is a Relational Database Management System (RDBMS) and the second is a Hierarchical Storage Management System (HSM)
• Utmost databases usage the RDBMS model; Oracle similarly uses the RDBMS model.
• Another one is a Hierarchical Storage Management System (HSM)
• Next is the Information Management System (IMS) of IBM.
• Last is the Integrated Database Management System (IDMS) of CA.

Q12). Highlight a few ways to join methods in the Oracle Database

Join approaches are of mostly 3 types-

• Merge Join – Categorization both the tables by means of join key and then combine the rows which are organized.
• Nested loop joins – It becomes an outcome set after smearing filter circumstances based on the outside table. Formerly it joins the inner table with the individual consequence set.
• Hash join –It usages hash algorithm primary on the minor table and then on the additional table to acquire joined columns. After that corresponding rows are reimbursed.

Q13). Explain the mechanisms of the logical data model.

Mechanisms of the logical data model are:

• Entity – Entity mentions to an object that we practice to store data. It has its particular table.
• Attribute – It signifies the info of the entity that we are involved in. It is stowed as a column of the table and has a specific data type related to
• Record – It mentions to a collection of all the possessions related to an object for one exact condition, signified as a row in a table.
• Domain-It is the established of all the conceivable values for a particular attribute.
• Relation – Signifies a relation between two entities.

Q14). What is the difference between the Logical and Physical data models?

Logical data model signifies a database in standings of logical objects, such as objects and relations. Whereas the Physical data model signifies database in standings of physical objects, such as tables and limitations.

Q15). Explain the meaning of query?

A query in usual terms is a query, simple sufficient. It is the declaration that is speaking to the database in demand to Create, Read, Inform or Remove (CRUD) data. While numerous times a query is a definite query asking for a response, it can also be the declaration to adapt, insert, or eliminate data in the database as well.

Q16). Explain in detail the function of the ‘SELECT’ command in the Oracle database.

SELECT in the definition of an SQL request triggers a query to the database. It aspects transversely the quantified table(s), finds the information you are seeing for, and then offers it to the operator for contemplation. Depending on the inquiry, this can be a dreadful lot of information, so again, requesting the correct query is serious.

Q17). What is normalization in Oracle?

Normalization refers to the process of organizing the fields and tables of a relational database in Oracle used to minimize the redundancy and dependency of a database. It helps in saving the storage space and makes sure of the consistency of our data.

Q18). What are the different forms of normalization?

There are six different normal forms as follows-

• First Normal Form
• Second Normal Form
• Third Normal Form
• Boyce Codd Normal Form
• Fourth Normal Form
• Fifth Normal Form

Q19). What are the types of disk components available in Oracle?

These are the physical components available in the disk-

• Redo Log files
• Data files
• Control files
• Password files
• Parameter files

Q20). Elucidate the difference between a cluster and a grid.

Clustering is one of the technologies which is used to create a grid infrastructure in Oracle. Simple clusters are characterized by static resources for specific applications by the specific owners. Grids can consist of multiple clusters and are forceful resource pools shareable which is sharable among many different applications and users. A grid does not by default assume that all the servers in the grid are running on the same set of applications whereas a cluster does make that presumption.