Re: A question about buffer cache

I believe this is all done by server processes. The following excerpts come from the Oracle Performance Tuning Class:

server processes read data from datafiles into the buffer cache DBWR writes data from the buffer cache into the datafiles

the dirty list points to blocks in the buffer cache that have been modified,

   but not written to disk

when a server needs a block it follows these steps:

(1) looks for the block in the buffer cache
(2) if not in cache, server reads the block from datafile
(3) while searching the LRU list the server moves dirty blocks to dirty list.
(4) if dirty list exceeds its size threshold server signals DBWR to flush
(5) when free block is found the server reads the block in from datafile.

HTH
Roy

In article <36889D34.D982F94D_at_fujitsu.com.hk>,   geoffreyh_at_fujitsu.com.hk wrote:
> Dear all,
>
> I would like to know whether "a user process" or "a server process"
> searches the LRU list and moves dirty buffers into the dirty list?
>
> I read the Concept manual as well as the ILT course manual and I'm not
> sure which one is correct, would anybody please advise?
>
> Thanks.
>
> cheers,
> Geoffrey
>

-----------== Posted via Deja News, The Discussion Network ==---------- http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own Received on Tue Dec 29 1998 - 15:01:22 CST