Re: Interaction between databse cache, DBWR and datafiles

From: Sybrand Bakker <gooiditweg_at_nospam.demon.nl>
Date: Thu, 30 Jan 2003 19:46:17 +0100
Message-ID: <blsi3vcp8cla0fkr8ci2b689jlof00ubao@4ax.com>

On 30 Jan 2003 07:07:48 -0800, wilsonr_at_logica.com (Rachel Wilson) wrote:

>* if another process wants access to a dirty buffer i think it is
>flagged as having "waiters" but i'm not sure what happens to the
>buffer - does it get written to disk and then read back in? does the
>second modification get made immediately so only one write occurs?

If a transaction is going on on a buffer other processes will be referred to the before image in the rollback segment. Oracle automatically piggy backs 'hot' blocks, the block will not be written out and read back.

Sybrand Bakker, Senior Oracle DBA

To reply remove -verwijderdit from my e-mail address Received on Thu Jan 30 2003 - 12:46:17 CST