DataBase Administrator (DBA) Interview Questions and Answers
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157. What is an Index Segment?
Each Index has an Index segment that stores all of its data.
158. 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
159. What are the different type of Segments?
Data Segment, Index Segment, Rollback Segment and Temporary Segment.
160. What are Clusters?
Clusters are groups of one or more tables physically stores together to share common columns and are often used together.
161. What is an Integrity Constrains?
An integrity constraint is a declarative way to define a business rule for a column of a table.
162. 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.
163. What is an Extent?
An Extent is a specific number of contiguous data blocks, obtained in a single allocation, and used to store a specific type of information.
164. What is a View?
A view is a virtual table. Every view has a Query attached to it. (The Query is a SELECT statement that identifies the columns and rows of the table(s) the view uses.)
165. What is Table?
A table is the basic unit of data storage in an ORACLE database. The tables of a database hold all of the user accessible data. Table data is stored in rows and columns.
(Continued on next part...)