Oracle interview Questions
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Oracle Concepts and Architecture
Database Structures
Qus. . Can a view based on another view?
Ans: Yes.
Qus. . What are the advantages of views?
Ans: - 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 perspective from that of the base table.
- Store complex queries.
Qus. . What is an Oracle sequence?
Ans: A sequence generates a serial list of unique numbers for numerical
columns of a database's tables.
Qus. . What is a synonym?
Ans: A synonym is an alias for a table, view, sequence or program unit.
Qus. . What are the types of synonyms?
Ans: There are two types of synonyms private and public.
Qus. . What is a private synonym?
Ans: Only its owner can access a private synonym.
Qus. . What is a public synonym?
Ans: Any database user can access a public synonym.
Qus. . What are synonyms used for?
Ans: - 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.
Qus. . What is an Oracle index?
Ans: 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.
Qus. . How are the index updates?
Ans: Indexes are automatically maintained and used by Oracle. Changes to
table data are automatically incorporated into all relevant indexes.
Qus. . What are clusters?
Ans: Clusters are groups of one or more tables physically stores together
to share common columns and are often used together.
Qus. . What is cluster key?
Ans: The related columns of the tables in a cluster are called the cluster
key.
1 2 3 4 5 6 7 8 9 10 11 12 13
14 15
