Oracle freshers Faqs Vip

Oracle freshers Faqs Vip

Oracle Interview Questions And Answers


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12. Do View contain Data ?

Views do not contain or store data.

13. Can a View based on another View ?

Yes.

14. What are the advantages of Views ?

Provide an additional level of table security, by restricting access
to a predetermined set of rows and columns of a table.
Hide data complexity.
Simplify commands for the user.
Present the data in a different perpecetive from that of the base
table.
Store complex queries.

15. What is a Sequence ?

A sequence generates a serial list of unique numbers for numerical
columns of a database's tables.

16. What is a Synonym ?

A synonym is an alias for a table, view, sequence or program unit.

17. What are the type of Synonyms?

There are two types of Synonyms Private and Public.

18. What is a Private Synonyms ?

A Private Synonyms can be accessed only by the owner.

19. What is a Public Synonyms ?

A Public synonyms can be accessed by any user on the database.

20. What are synonyms used for ?

Synonyms are used to : Mask the real name and owner of an object.
Provide public access to an object
Provide location transparency for tables,views or program units of a
remote database.
Simplify the SQL statements for database users.

21. What is an Index ?

An Index is an optional structure associated with a table to have
direct access to rows,which can be created to increase the
performance of data retrieval. Index can be created on one or more
columns of a table.

22. How are Indexes Update ?