Oracle BPM Interview Questions & Answers (Part-1)

Question :What is Level 0, Level 1 backup?

Answer : A level 0 incremental backup, which is the base for subsequent incremental backups, copies all blocks containing data, backing the data file up into a backup set just as a full backup would. A level 1 incremental backup can be either of the following types:

A differential backup, which backs up all blocks changed after the most recent incremental backup at level 1 or 0

A cumulative backup, which backs up all blocks changed after the most recent incremental backup at level 0

Question :How do you setup the RMAN tape backups?

Answer : Configure channel as SBT_TAPE and use "ENV" parameter to set the tape configurations.

Question :What is the init parameter specify the minimum number of days that Oracle keeps backup information in the control file?

Answer : You can use the CONTROL_FILE_RECORD_KEEP_TIME parameter to specify the minimum number of days that Oracle keeps this information in the control file.

Question :What is the difference between validate and crosscheck ?

Answer : The restore ... validate and validate backupset commands test whether you can restore backups or copies. You should use:

- restore : validate when you want RMAN to choose which backups or copies should be tested.

- validate backupset when you want to specify which backup sets should be tested.

Question :How do I go about backing up my online redo logs?

Answer : Online redo logs should never, ever be included in a backup, regardless of whether that backup is performed hot or cold. The reasons for this are two-fold. First, you physically cannot backup a hot online redo log, and second there is precisely zero need to do so in the first place because an archive redo log is, by definition, a backup copy of a formerly on-line log. There is, however, a more practical reason: backing up the online logs yourself increases the risk that you will lose

Question :What is backup set?

Answer : RMAN can store backup data in a logical structure called a backup set, which is the smallest unit of an RMAN backup. A backup set contains the data from one or more data files, archived redo logs, or control files or server parameter file.

Question : What is Channel? How do you enable the parallel backups with RMAN?

Answer : Use the ALLOCATE CHANNEL command to manually allocate a channel, which is a connection between RMAN and a database instance. To enable the parallel backups, allocate multiple manual channels in the run block or configure parallelism

CONFIGURE DEVICE TYPE DISK PARALLELISM 4 BACKUP TYPE TO BACKUPSET;

Question : What is auxiliary channel in RMAN? When do you need this?

Answer : An auxiliary channel is a link to auxiliary instance. If you do not have automatic channels configured, then before issuing the DUPLICATE command, manually allocate at least one auxiliary channel within the same RUN command. When a Duplicate Database created or table space point in time recovery is performed Auxiliary database is used. This database can either on the same host or a different host.