1Z0-030 Oracle9i: New Features for Administrators Training Course

Demo Question 7.

What are the steps the server process goes through when it needs to access a particular data block into the buffer cache?

A. The server process must always read the current version of a data block from the data files into the buffer cache. Once it is there, the server process can access the data block.
B. The server process always contacts the DBWR process to read the current version of a data block from the data files into the buffer cache. Once it is there, the server process can access the data block.
C. The server process first checks to see if the block is already in the buffer cache using a hash function. If it is already in memory, the server process uses it. If the block is not in memory, the server process reads the data block into the buffer cache. Once it is there, the server process can access the data block.
D. The server process first checks if the block is already in the buffer cache using a hash function. If it is already in memory, the server process uses it. If the block is not in memory, the server process contacts the DBWR process to read the data block into the buffer cache. Once it is there, the server process can access the data block.


Display Answer

Answer: C

Explanation: