> On Fri, 2003-02-14 at 17:00, Brunzema, Martin wrote: > > > > > > > -----Original Message----- > > > From: [EMAIL PROTECTED] > > > [mailto:[EMAIL PROTECTED]] > > > Sent: Freitag, 14. Februar 2003 12:04 > > > To: Brunzema, Martin > > > Cc: [EMAIL PROTECTED]; > > > [EMAIL PROTECTED] > > > Subject: Antwort: RE: Backup and Recovery > > > > > > > > > Hi Martin, > > > could you please explain it once again, using more single steps? > > > I tried several ways with no working result. I talked to > > > others who tried > > > your solution, > > > unfortunately nobody made it work. :-( > > > > > > Hi, > > > > this is no real "standby"-sloution, but a cheap version > > of it using the log-backup to keep the standy-db up to > > date. > > > > Here are the steps to perform it (i also didn't implement > > this solution, but it should work) > > > > > > master-db: start database > > master-db: create a complete databackup > > standby-db: install the standby-db from the databackup > > > > now you have two identical databases. If you change data > > on the master-db, you want to do this changes also auto- > > matically on the standby-db. You can perform this by > > using the logsaves of the master-db, which contains all > > the change-operations. You only have to do periodically > > a save-log on the master-db and to restore them into > > the standby-db. > > > > For a delay of one hour, you should establish save/restore > > log every hour as follows: > > > > master-db: save-log into file.xxx (xxx is the automatically > > appended number) > > > > copy file.xxx to the standby-db > > > > standby-db: restore log from file.xxx-1 > > (do not restore file.xxx, but the predecessor in > > order to maintain your delay of one hour) > > > > > > In case of a crash of the master-db you can either > > - restore the rest of the logsave > > - additionally do a save log on the master in cold-mode > > and restore it also > > - or just doing a restart by using recover_ignore > > > > The delay will not be exactly one hour, but in the intervall > > 1 to 2 hours. You can adjust it by changing interval of > > your logsave. > > > > > > HTH, Martin > > > > _______________________________________________ > > sapdb.general mailing list > > [EMAIL PROTECTED] > > http://listserv.sap.com/mailman/listinfo/sapdb.general > > > So with your method Martin, we are obliged not to use the autolog > function, aren't we ? > > Would it be really much more expensive to deal with > incremental backup ?
You still may use the autolog-function, but an autolog-backup is started when a defined number of Log-Pages had been written. It is not possible to configure the autolog timedependend. Incremental backup handling is different for <= 7.3 and 7.4: For Version <= 7.3 the incrementell backup saves the changed pages since the last incremental OR complete backup. This means, it holds the same information as contained in the Log. The difference for recovery between log-backup and incremental backup is, that log-backup has to be executed (more time consuming) but you have also the possibility to recover everything. For Version 7.4 the incremental backup saves alle pages changed since the last COMPLETE BACKUP. So the number of pages will increase the longer the database is running while the size of the log-saves will remain constant (ok: depends on your workload). In 7.4 you also have the possibility to cancel a log-recovery and continue it with a "restore log until" command. By this you can exactly define the delay when restarting the standby-instance. e.g.: you issued some commands like recover_replace logmedium log logsave.012 recover_replace logmedium log logsave.013 recover_replace logmedium log logsave.014 recover_replace logmedium log logsave.015 Then your master crashes at 2003:06:13 16:08:44. You restart the standby-database by: recover_cancel recover_start logmedium log 015 UNTIL 20020613 15:0844 and evntl: recover_replace logmedium log logsave.016 regards, Martin _______________________________________________ sapdb.general mailing list [EMAIL PROTECTED] http://listserv.sap.com/mailman/listinfo/sapdb.general
