Sorry Email... About log switch, If don't use force switch log "alter system archive log current" and ...etc Normally, log switch (if have 3 groups) -> oracle will write log file group1 , and when it gets to the end of this set of files, it will switch to log file group2 ,and then group 3... and switch back to group1. So, A log switch on one instance of a RAC does not trigger log switches across one or more of the other instances. But if we use "archive_lag_target" initialization parameter, that will make all instances switch in the same time. http://download.oracle.com/docs/cd/B19306_01/server.102/b14237/initparams009.htm archive_lag_target -> oracle recommends for RAC (Multiple instances should use the same value) SQL> show parameter archive_lag_target NAME TYPE VALUE ------------------------------------ ----------- ------------------------------ archive_lag_target integer 3600 Surachart Opun http://surachartopun.com On Wed, Nov 11, 2009 at 1:33 AM, Rajesh Rao <Rajesh.Rao@xxxxxxxxxxxx> wrote: > Sorry, I mean, other than the alter system commands, Why and when would a > log switch on one instance of a RAC trigger cause log switches to happen > across one or more of the other instances? > > > > *From:* Surachart Opun [mailto:surachart@xxxxxxxxx] > *Sent:* Tuesday, November 10, 2009 1:24 PM > *To:* Rajesh Rao > *Cc:* oracle-l@xxxxxxxxxxxxx > *Subject:* Re: Log Switches in RAC > > > > If you are meaning switch log by manual... > > > > "alter system switch logfile" > > This command switches log on that instance. > > > > "alter system archive log current" > > > > This command switches log all instance in RAC > > > > Example: > > SQL> alter system switch logfile; > > > > System altered. > > > > SQL> alter system archive log current; > > > > System altered. > > > > > > Good Luck > > Surachart Opun > http://surachartopun.com > > On Wed, Nov 11, 2009 at 1:11 AM, Rajesh Rao <Rajesh.Rao@xxxxxxxxxxxx> > wrote: > > > > Why and when would a log switch on one instance of a RAC trigger cause log > switches to happen across one or more of the other instances? > > > > Thanks > > Raj > > This communication is for informational purposes only. It is not intended > as an offer or solicitation for the purchase or sale of any financial > instrument or as an official confirmation of any transaction. All market > prices, data and other information are not warranted as to completeness or > accuracy and are subject to change without notice. Any comments or > statements made herein do not necessarily reflect those of JPMorgan Chase & > Co., its subsidiaries and affiliates. This transmission may contain > information that is privileged, confidential, legally privileged, and/or > exempt from disclosure under applicable law. If you are not the intended > recipient, you are hereby notified that any disclosure, copying, > distribution, or use of the information contained herein (including any > reliance thereon) is STRICTLY PROHIBITED. Although this transmission and any > attachments are believed to be free of any virus or other defect that might > affect any computer system into which it is received and opened, it is the > responsibility of the recipient to ensure that it is virus free and no > responsibility is accepted by JPMorgan Chase & Co., its subsidiaries and > affiliates, as applicable, for any loss or damage arising in any way from > its use. If you received this transmission in error, please immediately > contact the sender and destroy the material in its entirety, whether in > electronic or hard copy format. Thank you. Please refer to > http://www.jpmorgan.com/pages/disclosures for disclosures relating to > European legal entities. >