fbchua

 Profile Answers by fbchua 

• Oct 17th, 2008

 

I Believe in designing a good backup strategy it will not only be simply backup but also a contingency plan. In this case you should consider the following:

1. How long is the allowable down time during recovery? - If short, you could consider using dataguard.

2. How long is the backup period? - If short, I would advise to use RMAN instead of user managed backup.

3.  If limited disk space for backup never use user managed backup.

4. If the database is large you could consider doing full rman backups on a weekend and do a incremental backup on a weekday.

5. Schedule your backup on the time where there is least database activity this is to avoid resource huggling.

6. Backup script should always be automized via scheduled jobs. This way operators would never miss a backup period.

7. Retention period should also be considered. Try keeping atleast 2 full backups. (current and previous backup).

So far this is all I could think of.

taya_ronak

 Profile Answers by taya_ronak 

• Dec 7th, 2008

 

Cold backup: shutdown the database and copy the datafiles with the help of
O.S. command. this is simply copying of datafiles just like any other text file
copy.

Holt backup: backup process starts even though database in running. The
process to take a hot backup is

1) sql> alter database begin backup;

2) copy the datafiles.

3) after copying
sql> alter database end backup;

Begin backup clause will generate the timestamp. it'll be used in backup
consistency i.e. when begin backup pressed, it'll generate the timestamp. During
restore, database will restore the data from backup till that timestamp and
remaining backup will be recovered from archive log.