Set - 7

Question 96 :

What is network database link?

Answer :

Network database link is created and managed by a network domain service. A network database link can be used when any user of any database in the network specifies a global object name in a SQL statement or object definition.


Question 97 :

What is data block?

Answer :

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.


Question 98 :

How to define data block size?

Answer :

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 data blocks. Block size is specified in init.ora file and cannot be changed latter.


Question 99 :

What is row chaining?

Answer :

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.


Question 100 :

What is an extent?

Answer :

An extent is a specific number of contiguous data blocks, obtained in a single allocation and used to store a specific type of information.