Comparison Table of Backup and Recovery

Oracle 9i Database backups	SQL Server 2000 Database backups
In oracle 9i, redo logs are used for backup purposes. Oracle 9i puts the database in archivelog mode and automatically backs up the redo log by a process called archiving.	In SQL Server 2000, transaction logs are backed up for the same purpose. But, this has to be done manually by the DBA, once they fill up. DBAs often set up a batch job that runs periodically to back up transaction log, to avoid the manual task. Batch job in SQL Server is not a very acceptable solution because it cannot adapt to changes in workload.
Oracle 9i supports online backup. RMAN ensures that during online backup, impact on performance is within an acceptable limit. RMAN checks for both availability and performance of the system.	SQL Server 2000 also has online backup capability, but users may experience performance degradation.
Oracle 9i backups are complete and fully self- contained. Oracle database can be recovered from any situation as long as a good backup is available.	SQL Server 2000 backups are not self- contained. Hence, if msdb is lost, database is recovered by installing original CD even, even if regular backups are performed.
Block media recovery feature of oracle 9i allows recovering only that block which is damaged and needs recovery. The rest of the file remains online and accessible	SQL Server cannot recover data in single block units. Full file needs to be taken offline, restored and recovered.
Supports on-line and offline database and redo log backups. Oracle supports a number of certified vendors equipments for backup.	SQL Server 2000 includes the capability to perform differential backups. Using this approach, backups run relatively quickly and are smaller in size than other types of backups. Moreover, differential backups may be performed while users access the database.
Oracle DBMS performs automatic recovery each time it is started.	SQL Server2000 performs automatic recovery by checking each database in the system each time its Windows NT/2000 Service is started.
Uncommitted data from Rollback segments is removed and online redo log files are searched for any information required at the time of recovery.	SQL Server transaction log has the combined functionality of an Oracle rollback segment and an Oracle online redo log. Transaction log keeps record of all changes to the database.
Oracle automatically creates and schedules a predefined backup job during database creation that implements the Oracle recommended strategy for backup management. The Oracle recommended strategy calls for backups to be made as follows: • Perform full database backup once • Subsequently perform incremental backups • Update full database backup image copy with incremental backups	In SQL Server, backup management is the burden of the DBA. A DBA has to first understand SQL Server architecture, learn about all the backup and recovery features that it provides, and then devise a strategy that provides the best possible recovery for the business needs. Once all this is done, the DBA then has to create the backup job that implements the strategy. This is another area where a DBA has to worry about one less thing in Oracle than in SQL Server.
Flashback query Users can make mistakes such as entering the wrong values or deleting the wrong set of rows. Oracle9I’s flashback query allows an administrator or a user to view the database at a point-in time in the past. Developers can use this feature to build self-service error correction applications, empowering end-users to undo and correct their errors without delay.	Flashback query Not Supported