That's why you use write cache only if it's "battery supported". Then it should be safe.
Igor Neyman, OCP DBA [EMAIL PROTECTED] ----- Original Message ----- To: "Multiple recipients of list ORACLE-L" <[EMAIL PROTECTED]> Sent: Friday, September 06, 2002 2:28 PM > > I'll take a shot at this. > > Don't have any write caching. Oracle may think that it has safely > committed the transactions and they are written to disk when they are in > fact only in cache. If the machine were to shut down ungracefully, i.e., > someone kicks out the plug, then your database would not be in a consistent > state. Granted, the odds are small, but is it worth the risk? If the > database is archived and you don't mind the increased chance of having to > do a recovery then I would say 0% read - 100% write. Oracle is doing it's > own read caching in the SGA and it's unlikely that the disk cache will > correctly anticipate Oracle's read requirements. Therefore, caching on the > read side is only likely to increase IO. Write caching does not lead to > any increased IO but it does have some small risk of producing an > inconsistent database. > > > > GKor > @rdw.nl To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> > Sent by: root cc: > Subject: cache settings NT > > 09/06/2002 > 04:18 AM > Please > respond to > ORACLE-L > > > > > > > Hi all > > I have the following question for you : > > what are the preferred values for the several cache settings on the fysical > disk units (NT W2K) > > e.g. 100 % read cache - 0 % write cache > 50% read cache - 50% write cache > > is there a difference between settings for an OLTP or DSS solution. > > etc > > anyone with an explanation > > vr. gr. > g.g. kor > rdw ict groningen > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > -- > Author: > INET: [EMAIL PROTECTED] > > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 > San Diego, California -- Public Internet access / Mailing Lists > -------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). > > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > -- > Author: Thomas Day > INET: [EMAIL PROTECTED] > > Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 > San Diego, California -- Public Internet access / Mailing Lists > -------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB ORACLE-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Igor Neyman INET: [EMAIL PROTECTED] Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
