Interview Questions.

Question 1. One Of My Control File Corrupted And I Am Unable To Start Database. Could You Tell Me How To Perform Recovery?

Answer :

If one among your manage report is lacking or corrupted then we've 2 options to get better it. Check alert.Log for specific name and vicinity of corrupted manage report. Delete it manually and replica from to be had relaxation of control report and rename it and start database. Another alternative is delete corrupted manipulate record and do away with call from parameter record/ spfile. After casting off said manipulate record from spfile, begin your database.

Question 2. What Is Incremental Checkpoint?

Answer :

In incremental checkpoint method, CKPT technique statistics lowest Low RBA to the manage file to keep advancing the Buffer checkpoint Queue (BCQ) to make clean and quickest Active Checkpoint Queue (ACQ).

Data Center Management Interview Questions
Question 3. Does Incremental Checkpoint Recorded In Alert.Log? How To Disable It?

Answer :

We can allow disable recording incremental checkpoint in alert.Log .We can enable/disable recording the usage of parameter log_checkpoints_to_alert=proper/false.

Question four. I Am Working As Oracle Dba In 24/7 Running Large Production Database. Size Of Database Is Around 800 Gb. We Take Hot Backup Every Day Night. But One Day At Around 4:00 Pm, By Mistake One Table Is Dropped By Application User. Table Is Very Important. How To Recover Said Dropped Table?

Answer :

If your database is running on Oracle 10g/11g/12c version then there may be new feature to be had known as Recycle bin. You can get better dropped desk from user_recyclebin or dba_recyclebin.

Question five. In Continuation Of Above Scenario, Recycle Bin Doesn't Enable In My Database Then How To Recover My Table? How To Disable It?

Answer :

Then you ought to need to restore backup on your UAT or take a look at database server and permit time based healing for applying all archives earlier than drop command execution. For an instance, practice records up to three:55 PM right here.

Emc Vmax Interview Questions
Question 6. In Continuation Above Scenario, Why I Should Need To Perform Recovery In Uat And Test Database Server? Can I Restore Backup In Production Database Server Too?

Answer :

Yes. You can. It is not advocated because your production database is large database and running 24/7 surroundings. Restoration and healing will take downtime. It is higher to carry out recuperation and restoration manner on UAT or Test database.

Question 7. What Is The Meaning Of Lgwr Sync And Lgwr Async In Log Archive Destination Parameter Of Standby Configuration?

Answer :

When use LGWR with SYNC, it approach as soon as network I/O initiated, LGWR has to wait for of entirety of network I/O before write processing. LGWR with ASYNC way LGWR doesn’t wait to finish network I/O and continuing write processing.

IDMS (Integrated Database Management System) Interview Questions
Question 8. How Can I Know My Require Table Is Available In Export Dump File?

Answer :

Create index file of export dump record using import with index file command. A text record could be generating with all table and index item call with quantity of rows. You can verify your require table object from this text file. If you are the use of datapump then there is parameter known as "sqlfile" in impdp.

Question 9. Archive Logs Are Being Generated Around 20gb In My Production Large Database. But One Day Almost Double Archives Were Generated. What Is The Reason Behind This? How Can I Check It?

Answer :

There are plenty of reason behind increasing length of data like If extra database modifications had been completed the usage of batch jobs or any special task like merging 2 database or records and many others. You can inspect exact root cause the use of enabling Log Minor utility.

IBM Tivoli Interview Questions
Question 10. How Do You Recover From The Loss Of Data File If Database Is Running In Archive Log Mode?

Answer :

We can carry out this restoration in 2 methods. One is open database mode and any other is database mount mode. After taking offline misplaced datafile, we are able to deliver database open and after that repair misplaced datafile from closing backup. After recovery of datafile we can carry out datafile degree restoration for making use of archive logs and make it on line. In database mount mode, we are able to repair datafile from backup and perform datafile healing the usage of "Recover datafile" command.

Question 11. What Is The Complete Recovery?

Answer :

During this restoration we're applying all database modifications the use of records log and make it to up to date. Complete recovery can be carried out complete database level or datafile level or tablespace stage. Main concept is to apply all facts modifications the usage of archive logs and convey database as much as current time.

Ibm Tivoli Netcool Omnibus Interview Questions
Question 12. Why We Should Need To Open Database Using Resetlogs After Finishing Incomplete Recovery?

Answer :

When we're performing incomplete restoration it way we convey database to past time or rewind time frame using change primarily based, cancel based totally or time based recovery. These all healing make database in previous nation of database. The forward series wide variety already to be had after performing restoration, due to mismatching of this sequence numbers and prior state of database, it wishes to open database with new sequence wide variety of Redo log and archive logs.

Data Center Management Interview Questions
Question thirteen. Why Export/information Pump Backup Called As Logical Backup?

Answer :

Export and datapump dump document would not backup or include any bodily structure of database like datafile, control document, redo log record, parameter record, password report. Instead of physical structure, export unload includes logical structure of database like definition of tablespaces, segments, schemas, facts of segments and many others. Due to these motives export and datapump sell off is called as logical backup.

Question 14. Have You Faced Any Recovery Scenario? Explain How You Resolved It?

Answer :

2 months back, a capacity table was dropped by means of an software developer on our massive 24/7 strolling manufacturing database. Immediately he informed us. We have standby database for our manufacturing database. We checked that information didn’t observe to standby database as much as dropped timing. We stopped archive making use of on standby at once and open database read only. Took export of dropped table and imported in manufacturing database. After completing suitable checking of desk, again we started out archive applying in standby database for fresh.

Question 15. Which Command I Should Need To Execute To Back Up Database Which Is Running On Noarchivelog Mode?

Answer :

Shutdown immediately. Because with out shutdown, we can not perform on line backup of database, which going for walks on NOARCHIVELOG mode. We ought to need to take bloodless backup of database. After smooth shutdown database reproduction of all datafiles, control documents, redo log files, password document, and parameter files.

EMC Interview Questions
Question sixteen. What Are The Steps Involved In Database Startup?

Answer :

Start an example, Mount the Database and Open the Database.

Question 17. What Are The Steps Involved In Database Shutdown?

Answer :

Close the Database; Dismount the Database and Shutdown the Instance.

Automatic Storage Management (ASM) Interview Questions
Question 18. What Is Restricted Mode Of Instance Startup?

Answer :

An instance can be started out in (or later altered to be in) restricted mode so that when the database is open connections are constrained handiest to the ones whose person debts were granted the RESTRICTED SESSION device privilege.

Emc Vmax Interview Questions
Question 19. What Are The Different Modes Of Mounting A Database With The Parallel Server?

Answer :

Exclusive Mode If the first instance that mounts a database does so in distinctive mode, handiest that Instance can mount the database.

Parallel Mode if the primary instance that mounts a database is commenced in parallel mode, other times which can be began in parallel mode also can mount the database.

Question 20. What Is Full Backup?

Answer :

A full backup is an operating machine backup of all statistics files, on-line redo log documents and manage file that constitute ORACLE database and the parameter.

Data Center Technician Interview Questions
Question 21. Can Full Backup Be Performed When The Database Is Open?

Answer :

No.

Question 22. What Is Partial Backup?

Answer :

A Partial Backup is any running machine backup quick of a full backup, taken whilst the database is open or shut down.

Question 23. What Is On-line Redo Log?

Answer :

The On-line Redo Log is a hard and fast of two or extra on-line redo documents that document all dedicated adjustments made to the database. Whenever a transaction is dedicated, the corresponding redo entries quickly stores in redo log buffers of the SGA are written to an on-line redo log file by using the background technique LGWR. The on line redo log files are utilized in cyclical style.

Storage Area Network Interview Questions
Question 24. What Is Mirrored On-line Redo Log?

Answer :

A mirrored on line redo log consists of copies of on line redo log documents bodily placed on separate disks; changes made to 1 member of the organization are made to all individuals.

IDMS (Integrated Database Management System) Interview Questions
Question 25. What Is Archived Redo Log?

Answer :

Archived Redo Log consists of Redo Log files that have done earlier than being reused.

Question 26. What Are The Advantages Of Operating A Database In Archivelog Mode Over Operating It In No Archivelog Mode?

Answer :

Complete database recovery from disk failure is viable best in ARCHIVELOG mode.

Online database backup is possible most effective in ARCHIVELOG mode.

Data Protection Manager Interview Questions
Question 27. What Is Log Switch?

Answer :

The factor at which ORACLE ends writing to at least one on-line redo log record and starts writing to some other is referred to as a log transfer.

IBM Tivoli Interview Questions
Question 28. What Are The Steps Involved In Instance Recovery?

Answer :

Rolling ahead to get better information that has not been recorded in records documents but has been recorded in the online redo log, together with the contents of rollback segments.
Rolling lower back transactions which have been explicitly rolled lower back or have now not been committed as indicated through the rollback segments regenerated in step a.
Releasing any sources (locks) held through transactions in system at the time of the failure.
Resolving any pending disbursed transactions undergoing a two-section dedicate at the time of the example failure.