Oracle Database(DBA) Interview Questions and Answers

What are the components of Physical database structure of Oracle Database?
ORACLE database is comprised of three types of files. One or more Data files, two are more Redo Log files, and one or more Control files.
What are the components of Logical database structure of ORACLE database?
Tablespaces and the Database's Schema Objects.
What is a Tablespace?
A database is divided into Logical Storage Unit called tablespaces. A tablespace is used to grouped related logical structures together.
What is SYSTEM tablespace and When is it Created?
Every ORACLE database contains a tablespace named SYSTEM, which is automatically created when the database is created. The SYSTEM tablespace always contains the data dictionary tables for the entire database. Explain the relationship among Database, Tablespace and Data file. Each databases logically divided into one or more tablespaces One or more data files are explicitly created for each tablespace.

What is schema?
A schema is collection of database objects of a User.
What are Schema Objects ?
Schema objects are the logical structures that directly refer to the database's data. Schema objects include tables,views,sequences,synonyms, indexes, clusters, database triggers, procedures, functions packages and database links.
Can objects of the same Schema reside in different tablespaces.?

Can a Tablespace hold objects from different Schemes ?
What is Data Block?
ORACLE database's data is stored in data blocks. One data block corresponds to a specific number of bytes of physical database space on disk.
How to define Data Block size?
A data block size is specified for each ORACLE database when the database is created. A database users and allocated free database space in ORACLE datablocks. Block size is specified in INIT.ORA file and cann't be changed latter.
What is Row Chaining?
In Circumstances, all of the data for a row in a table may not be able to fit in the same data block. When this occurs, the data for the row is stored in a chain of data block (one or more) reserved for that segment.
What is an Extent?
An Extent is a specific number of contiguous data blocks, obtained in a single allocation, used to store a specific type of information.

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What is the value of cot 4π/3 ?

Indian Politics

Article-24 of the Indian Constitution ‘Prohibition of employment of children in factories, etc’ deals with?

Article-134A of the Indian Constitution ‘Certificate for appeal to the Supreme Court’ deals with?


Who invented Aspirin?


A larger force on a rotating body results in larger?

What is the unit of the physical quantity, magnetic flux density?


The system of equations 2x + 4y = 6 and 4x + 8y = 8 is ?

Time and Distance

A thief is spotted by a policeman from a distacne of 100 m. When the policeman starts the chase, the thief also starts running. If the speed of the theif is 8 km / hour and that of the policeman is 10 km/hour, then how far will the theif have to run before he is overtaken?


Aman and Alok attempted to solve a quadratic equation. Aman made a mistake in writing down the constant term and ended up in roots (4, 3). Alok made a mistake in writing down the coefficient of x to get roots (3, 2). The correct roots of the equation are?

Compound Interest

The effective annual rate of interest corresponding to a nominal rate of 22% per annum payable half-yearly is?

Volume and Surface Area

If the volume of a cylinder is 2156 cubic cm and height is 14 cm, find its radius?


What is the equation of the line which passes through the points (2, 3) and (- 4, 1)?


In △ABC, the angle bisector of ∠A cuts BC at E. Find length of AC, if lengths of AB, BE and EC are 9 cm, 3.6 cm and 2.4 cm?

In a triangle, the length of the opposite side of the angle which measures 45° is 8√2 cm, what is the length of the side opposite to the angle which measures 90°?

General Knowledge of India

The boundary line between India and Pakistan is called?

Which city is located on the banks of the river Mahanadi?

Indian History

When was the battle of Haldighati fought?

In 1498, which Portuguese explorer discovered a new sea route from Europe to India?

General Knowledge of India

Chapchar Kut is a festival of which State?


In chemistry, soap is a salt of a ?

Indian Economy

Which of the following is a Direct tax?


Sauria lacertidae is the scientific name of?

Which of the following is a primary function of haemoglobin?


A factory buys 8 machines.3 Machine A, 2 Machine B and rest Machine C. Prices of the machines are 100000, 80000 and 45000 respectively.Calculate the average cost of these machines?


Ticket for an adult is 500 and a child is 200. 1 child goes free with two adults. If a group has 20 adults and 8 children what will be the discount the group get?