Database Writer - Quiz Explanation

The answers you selected are indicated below, along with text that explains the correct answers.

1.	The database writer's job is to: Please select the best answer.
	A.	Write data to the redo log files
	B.	Write data to the data files
	C.	Write control information to the control files
	D.	Write data to the database buffer cache
	The correct answer is B. The database writer's purpose is to find modified data blocks in the database buffer cache, and write these back out to the database files. This is how the database is updated.

2.	How many database writer processes does Oracle support? Please select the best answer.
	A.	Oracle supports an unlimited number of database writers.
	B.	Oracle supports only one database writer.
	C.	Oracle supports nine database writers.
	D.	Oracle supports ten database writers.
	The correct answer is D. Oracle supports up to ten database writers. The number ten was just an arbitrary choice on the part of Oracle. A digit is used as part of the process name, so the ten database writers would be `DBW0, DBW1, DBW2`, and so forth through `DBW10`.

3.	Which initialization file parameter controls the number of database writer processes in an Oracle instance? Please select the best answer.
	A.	`db_writer_processes`
	B.	`database_writer_max`
	C.	`dbwr_processes`
	D.	`dbw_process_count`
	The correct answer is A. The `db_writer_processes` parameter is used to set the number of database writer processes for an instance. To run with the maximum of ten for example, you would add the line “`db_writer_processes=10`” to your initialization file.