Q1. Describe three ways to backup an Oracle database
1. Incremental backups - this method will store only blocks that have changed since the previous backup. This will allow backups to be more compact and will provide faster recovery.
2. Binary compression - this method is integrated with Oracle Database and will reduce the size of the backups
3. Automated database duplication - creates a copy of your database with various storage configurations, specifically direct duplication between ADM databases
Q2. Describe the advantages/disadvantages and what is happening between archivelog mode and no archivelog mode. How does it affect backup and recovery?
Q3. Describe the jobs mechanism in Oracle. How are they scheduled?
Q4. We've been using pluggable databases all course long....describe the benefits of using pluggable databases. Why would you not use a pluggable database?
Q5. Describe the jobs mechanism in Oracle. How are they scheduled?
The choice of using ARCHIVELOG mode or not depends on system requirements. ARCHIVELOG mode allows for full backups and should be enabled for mission-critical data. If a database is in NOARCHIVELOG mode, then a backup can only be recovered to the point of the last full backup. Any additional changes made after this point are not logged, so they cannot be recovered. Also, in this mode, tablespace backups cannot be performed while the database is online. They must be performed while the database is closed (Choosing Between NOARCHIVELOG and ARCHIVELOG Mode, n.d.).
ARCHIVELOG mode essentially enables the use of redo logs to archive transactions. It offers three advantages:
A full database recovery can be performed with a combination of the last full database backup and the online redo log files.
You can use a backup taken while the database is open and in normal use.
You can keep a redundant, standby database current with its original counterpart by continuously applying the redo log produced by the original database to the standby.
The one major disadvantage of ARCHIVELOG mode is that it requires additional space in order to store the log information.
NOARCHIVE mode does have its advantages. Because there is no writing of transactions to a redo log, performance is increased.
To perform a "cold" backup in NOARCHIVELOG mode, the following steps are required:
Shut down the database
Create backup copies of all the data files, control files, and temporary database files
Restart the database
To perform a "hot" back with ARCHIVELOG mode, the following steps are required:
Alter the database/tablespace into backup mode
Copy the data files with an OS utility
Alter the database/tablespace out of backup mode
Archive the current online redo log
Backup the control file
Backup any archive redo log files generated during the backup