Oracle 11g Architecture Interview Questions and Answers for Experienced - 2

Question: 6

How do you control the maximum number of redo log files in a database?

The maximum number of redo log files can be controlled by the parameter MAXLOGFILES.

Question: 7

When does DBWR write to the data file?

Following are the situations when DWBR writes to the data file.

When checkpoint occurs

When number of dirty blocks reaches a threshold

Every three seconds due to timeout

When server process needs free space in buffer cache to read new blocks.

Question: 8

How can you backup the parameter files?

RMAN can be used to backup SPFILE with control file if CONFIGURE CONTROLFILE AUTOBACKUP is ON.

The following RMAN command can be used to backup the control file:

RMAN> CONFIGURE CONTROLFILE AUTOBACKUP ON;

The following RMAN command can be used restore an SPFILE:

RMAN> RESTORE CONTROL FILE FROM AUTOBACKUP;

Question: 9

What is large pool?

Oracle large pool is an optional memory component of the Oracle database SGA. This area is used for providing large memory allocations in many situations that arise during the operations of an Oracle database instance.

Session memory for the shared server and the Oracle XA interface for distributed transactions

I/O server processes

Parallel query buffers

Oracle backup and restore operations using RMAN

Large pools plays an important role in Oracle database Tuning since the allocation of the memory for the preceding components; otherwise, it is done from the shared pool. Moreover, due to the large memory requirements for I/O and RMAN operations, the large pool satisfies the requirements instead of depending on the Shared Pool Area.

Usage of a Large Pool Area allows the shared pool to primarily cache Structured Query Language (SQL) and avoid the overhead caused by shrinking the SQL Cache Area.

Question: 10

What are the advantages of using SPFILE?

SPFILE supports dynamic changes in parameter values. The changes in SPFILE can only be made by using the Oracle statements; therefore, there is no chance of accepting impossible changes as it will be checked by the system. As a result, chances of human errors are reduced.

Moreover, back up of SPFILE is possible through RMAN.