Backup & Recovery in Oracle Apps Database
Based on lots of request from readers of this blog I am posting on Backup & Recovery of Oracle Apps 11i database & application tier.
I’ll discuss on How to troubleshoot load balancer in oracle Apps after Backup & Recover.
You might have read in Oracle Documentation lot of time to backup your system before applying patch or before database Upgrade or changing any file or table. Today you will see how to take backup of table, file, database or applications (I am covering only basic things on backup)
How to backup a file/directory ?
This is most common & very basic thing in taking backup, backup is snapshot of any file at a particular time . In order to take backup of file/directory so that it can be recovered at later stage (In case of any issues)
cp filename filename
If you want to backup directory you can use
cp -R dir dir.bak
If directory is quite big lets assume APPL_TOP which is around 11GB you can tar (zip) utility in linux.
tar -cvf dir.tar dir ( Where -c is compress , v is verbose, f is file )
to restore backed up directory use -x extract option like
tar -xvf dir.tar
How to backup a table ?
If you are a DBA you will find this bit silly but you can use create table as assume you want to backup table FND_USERS to table FND_USERS_BAK , you can use
SQL> create table FND_USERS_BAK as select * from FND_USERS;
Though you can use imp/exp feature of database as well to backup a atble.
What are two main backup categories for Database ?
Broadly you have Cold Backup & Hot backup option with database.
Cold backup : is database backup which you take when database is down
Hotbackup : is database backup during which database is available to user . For Hotbackup database should be in archive log mode. Tablespaces should be in begin backup mode while copying data files.
Advantages of Cold backup :
Easy to implement, No need to convert database in to archive.
Disadvantage of Cold Backup :
Services are not available during backup, not acceptable in production
Advantages of Hot backup :
Users can access database & application during backup
Disadvantages of Hot Backup :
Difficult to implement initially, extra space for archive logs
For Cold Backup of Database & Applications :
–Shut down application tier services using adstpall.sh
–Shutdown database listener & database
–Copy file system (middle Tier & Database tier including software & datafiles to tape or harddisk ). You can zip or tar as well to reduce size of backup as mentioned above via tar -cvf
–Once backup is over start database & db listener
–Start Application Tier
For Hot backup of Database & Applications :
–Make sure database is in Archive log mode ( How to check & how to convert coming tomorrow)
–Put tablespaces in to begin backup Mode
–Create backup control file
— Copy datafiles , log file, control files
–Put tablespaces into end backup Mode
— Copy oracle software & middle tier software as mentioned in cold backup mode
Backup done
How to put tablespaces into begin or end backup mode
Wait for tomorrow’s post …
If you want to check Oracle Apps DBA Interview Questions check at
http://teachmeoracle.com/interview.html ( Around 15 pages & 90 questions)
*Those who posted interview questions to me, wait for some time as I am very busy right into project. I’ll try to respond you before end of this week .