If you use logmode=demo you are loosing your log backup history and so log backups are not permitted. This is true for all releases where "demo" is available. The same is true if log writing is disabled. So "demo" writes to the log device but the does not need to be saved. The log can always be overridden until the last savepoint position.
"log writing off" is new in 7.4 and hast no equivalence in <=7.3 and hast nothing to do with log backups. regards Uwe > -----Original Message----- > From: Warga (ext_Zip) Marco > [mailto:[EMAIL PROTECTED]] > Sent: Mittwoch, 11. Dezember 2002 11:06 > To: Hahn, Uwe; 'Watz'; [EMAIL PROTECTED] > Subject: RE: Question on 7.4 LOG_MODE > > > Ok thanks for the detailed explanation :) > > Lets see if I got it right... > > The LOG_MODE=DEMO in SAPDB <= 7.3 did indeed save logs needed > to get to the > last commit state after restart but not archive those in the > log devspace > that were created before the last savepoint (and therefore > not necessary for > restart anymore) ? > > And does SINGLE/OFF in the current 7.4 DBM GUI correspond to > the previous > SINGLE/DEMO setting (for now, until the final 7.4 release) ? > Or is actually log saving diabled with this setting and I > cannot make any > persistent changes (lost after shutdown/restart) until I set > it back to > SINGLE for now until you have LOG_BACKUP=NO ready in february? > > One more question...will the log devspace still be needed in > 7.4 for the > LOG_BACKUP=NO and the new "switching off log writing" setting? > > > > -----Original Message----- > > From: Hahn, Uwe [mailto:[EMAIL PROTECTED]] > > Sent: Mittwoch, 11. Dezember 2002 10:09 > > To: 'Watz'; [EMAIL PROTECTED] > > Subject: RE: Question on 7.4 LOG_MODE > > > > > > You recognized some changes which where done in 7.4. > > > > Logmode: > > > > 7.3 LOG_MODE=SINGLE => 7.4.current LOG_MODE=SINGLE => > > 7.4.develop LOG_MIRRORED=NO > > 7.3 LOG_MODE=DUAL => 7.4.current LOG_MODE=DUAL => > > 7.4.develop LOG_MIRRORED=YES > > 7.3 LOG_MODE=DEMO => 7.4.current disabled/removed => > > 7.4.develop LOG_BACKUP=NO (default: YES) > > > > In addition 7.4 knows a very risky feature. You can switch > > off log writing for transactions. But you have to be aware > > that you commit changes and they are NOT durable because a > > restart resets the database state to the last savepoint. This > > is the main difference between switing off log writing and > > LOG_BACKUP=NO (previously known as logmode=demo). In the last > > case you can recover to the last commit written to the log. > > > > Shutdown: > > > > 7.4 does not know the SHUTDOWN QUICK. There is only one > > shutdown which changes the kernels state to offline. > > 7.4.current: If during shutdown there are open write > > transactions these transactions receive a cancel request and > > are forced to rollback. The shutdown waits until the > > REQUEST_TIMEOUT is reached and then a savepoint with > > reason=shutdown is triggered and the kernel becomes offline. > > 7.4.develop: The kernel writes the savepoint with > > reason=shutdown and switches to offline immediatly. This > > behaviour normally makes it obsolete to call db_stop. > > > > regards > > Uwe > > > > > -----Original Message----- > > > From: Watz [mailto:[EMAIL PROTECTED]] > > > Sent: Mittwoch, 11. Dezember 2002 00:17 > > > To: [EMAIL PROTECTED] > > > Subject: Question on 7.4 LOG_MODE > > > > > > > > > Hi, > > > > > > I was wondering if the DEMO logmode was removed in SAPDB > > 7.4. Instead > > > of SINGLE/DEMO theres now a SINGLE/OFF setting in DBM GUI, > > and setting > > > the database to SINGLE/OFF switched off the log indeed > but the old > > > parameter LOG_MODE still stays on SINGLE and not DEMO like in the > > > previous versions (?). Is the LOG_MODE parameter not used > > anymore in > > > 7.4 ? > > > > > > And another thing....is just the "Stop" button on the > > > database shutdown dialog in DBM GUI removed for 7.4 > > > installations or is the actual db_stop DBM server command > > > disabled for those ? > > > Previously the box had something like "shutdown/shutdown > > > quick/cancel" as far as I remember. > > > > > > I migrated an R/3 testdrive installation successfully from > > > SAPDB 7.3 to 7.4 today (with a new dbadaslib though to > > > support 7.4), worked just as described in the migration > > > manual on the sapdb.org site and no issues so far :) > > > > > > Watz > > > > > > _______________________________________________ > > > sapdb.general mailing list > > > [EMAIL PROTECTED] > > > http://listserv.sap.com/mailman/listinfo/sapdb.general > > > > > _______________________________________________ > > sapdb.general mailing list > > [EMAIL PROTECTED] > > http://listserv.sap.com/mailman/listinfo/sapdb> .general > > > _______________________________________________ sapdb.general mailing list [EMAIL PROTECTED] http://listserv.sap.com/mailman/listinfo/sapdb.general
