RE: cache settings NT
thanks for your explanation, i'll go for the 0% read - 100% write cache. > -Oorspronkelijk bericht- > Van: Igor Neyman [SMTP:[EMAIL PROTECTED]] > Verzonden:vrijdag 6 september 2002 22:43 > Aan: Multiple recipients of list ORACLE-L > Onderwerp: Re: cache settings NT > > 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: rootcc: > > 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
Re: cache settings NT
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: rootcc: > 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).
Re: cache settings NT
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: rootcc: 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).
