DBWR process

[Rahulbatra]

I am interested in Oracle database administration and I have started to study a book on this. I want to know the responsibilities of DBWR process which is not in the book that I possess. Can someone highlight on this.

[oracleobsessed]

DBWR..Database Writer is one of the mandatory oracle processes.Its responsibility includes writing data blocks from memory (buffer cache) to the hard disk. there are certain times during the normal database activity where dbwr is invoked to write blocks on disk one of which is the checkpoint event. On each checkpoint event blocks that havent been written to the disk from the last checkpoint event are written to disk and made permanent.

[caradoc]

Fantastic discussion going around. Is there any Database Reader process as you have explained Database Writer.If so what is the process called.

[oracleobsessed]

a dbwr process writes from memory to disk so that once u shutdown ur database every thing that u previously had in ur memory (for faster procesing) in written safely to disk.
what wud be a reader process in oracle doing?....u are the reader who wants to read useful information out of oracle db, once u connect to oracle a server session is created on your behalf that reads data from disk and places it to memory(buffer cache)...so there are as many server processes or reader processes (as u may call them) as # of users that connect to the database or sql.

[Ralph]

Very nice explanation about the process DBWR. Thanks for such great replies.