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.?
Yes.
Can a Tablespace hold objects from different Schemes ?
Yes.
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.
What is a Segment?
A segment is a set of extents allocated for a certain logical structure.
What are the different types of Segments?
Data Segment, Index Segment, Rollback Segment and Temporary Segment.
What is a Data Segment?
Each Non-clustered table has a data segment. All of the table's data is stored in the extents of its data segment. Each cluster has a data segment. The data of every table in the cluster is stored in the cluster's data segment.
What is an Index Segment?
Each Index has an Index segment that stores all of its data.

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Physics

Atmospheric pressure at sea level equals ?

General Knowledge of India

Which of the following dance forms was introduced by the great Vaishnava saint and reformer Mahapurusha Sankaradeva ?

Which of the following is the only classical dance of india having links with Muslim culture and represents a unique synthesis of Hindu and Muslim genius in art ?

Time and Distance

Starting from the same point at the same time, Ruhan and Yuvan had to reach the same destination. While Ruhan drove at 45 km/hr, Yuvan was slower by 5 km/hr. If Yuvan arrived at the destination an hour after Ruhan did, the distance covered by each, in Kilometres, was ?

Simple Interest

A sum of money was invested at a certain rate of simple interest for 4 years. Had the sum been invested at a rate 3% higher than the actual rate, the interest earned would have been 720 Rs more. Find the sum initially invested?

Ratio and Proportion

A bag contains red, blue and black balls. The ratio of red to blue balls is 3 : 5. The ratio of black to red balls is 3 : 4. What is the ratio of blue to black balls?

Profit and Loss

Selling a pack of incense sticks for 136 Rs resulted in a loss of 15%. To make a profit of 10%, the selling price should be ?

Percentage

23% of a bucket full of diluted milk was water. If the quantity of pure milk in the bucket was 15.4 liter, then the capacity of the bucket was ?

Average

The average of the marks obtained by three girls in a test was twice the average of the marks obtained by eight boys in that test. If the total marks obtained by all these examinees was 168, find the average marks each of the girls obtained ?

Pipes and Cistern

44 pipes can fill a large water tank in 27 hours. How many hours it take for 66 pipes to fill four such tanks ?

HCF and LCM

A natural number, when divided by 3, 4, 5, 6, and 7 respectively, leaves corresponding remainder of 2, 3, 4, 5 and 6. What is the smallest of all such numbers fulfilling the above condition ?

Coding-Decoding

If in a certain code language, PRINT is written as 34825 and TRUE is written as 5479. Then, how will TENURE be written in that language?

Order Sequence

Arrange the given words from smallest to biggest-
1.Jug
2.Mug
3.Bucket
4.Drum
5.Cup

Statement and Conclusion

Statements
All socks are shoes
Some shoes are black

Conclusions
I. Some shoes are socks.
II. No scoks is black

Numbers

The difference between the place value of 4 and 2 in the number 833749502 is ?

Analogy

GIKM : HJLN :: PRTV : .........?

Order Sequence

In a row of girls, Nanda is eighth from the left and Chanda is nineteenth from right. When Nanda and Chanda interchange their positions, Chanda becomes twnty-third form right. How many girls are there in the row?

Analogy

Summer: Day :: Winter : ........?