Order and noorder options are relevant only for the OPS/RAC configurations because that is the only way that the sequence numbers may be returned out of order. If the sequence is not cached, then you'll suffer a logical read and a physical write each time you query the sequence. What will be a performance impact? It depends primarily on you disk configuration, whether your database is a file system one or is it on raw devices and how much cache are you having on your disk controllers.
> -----Original Message----- > From: Thomas Day [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, October 09, 2002 11:54 AM > To: Multiple recipients of list ORACLE-L > Subject: Re: sequence numbers > > > > If the sequence is not cached then Oracle has to generate a > new sequence > number for every record inserted (CPU cycles). NOORDER is > the default so > that won't slow you up. If you're doing bulk loads why not cache the > sequence numbers? Is it important that there be no gaps? Even with > NOCACHE you can get gaps. If a sequence number is generated > but the row > (insert or create) is not COMMITed the sequence number is not > rolled back. > > Unless there are fewer than 100 rows to be inserted I'd go with some > caching. > > > > > > April Wells > > <awells To: Multiple > recipients of list ORACLE-L <[EMAIL PROTECTED]> > @csedge.com> cc: > > Sent by: root Subject: > sequence numbers > > > > > 10/09/2002 > > 10:54 AM > > Please > > respond to > > ORACLE-L > > > > > > > > > > > I have been given create scripts for sequences to be used in > tables that > will be loaded via bulk loads. How huge is the potential > performance hit > if I take out the cache 20? > > > April Wells > Oracle DBA > There is neither good nor bad, but thinking makes it so. -Shakespeare > > > << Attachment Removed : InterScan_Disclaimer.txt >> > > > > -- > Please see the official ORACLE-L FAQ: http://www.orafaq.com > -- > Author: Thomas Day > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > 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: Gogala, Mladen INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- 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).
