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Oracle DBA QuestionsWhat happen when we kill smon?What happen when we kill pmonWhat is fracture block and how to fix itWhat is corrupted block and how to fix itWhat are the oracle threads are going to start ,when we start the databaseHow to check index is working properly ,what are the steps to be taken and on what basis we have to decide particular index has to rebuild not all indexesWhat steps to be taken if receive a call that performance has gone down as DBA what steps has be takenWhat possible error can we able to see in alert fileSudden if performance go down what steps to be taken without using alert file is coz size 3m and we don't want to user alert file how to find the problem and how to fix itIf users are not able to connect database or database is down what preliminary steps to takenWhat actually do in oracle when we take hot backup where actually modified blocks are written?What should be RAM for 50gb database on what basis we have to decide the ramCan we able to connect database using listener instead of TNS namesNormally on daily basis what are the jobs DBA has to do on daily basis?Can we able to create physical standby database using hot backup if yes howIs there is something concurrent user connections are limit if yes how can we increase user connection interview said by using LISTENER FILE If we want to write query how write efficient query and how to make execution plans
ashok
- Aug 30th, 2011
When process monitor kills we can't remove locks on tables,
ianilreddy
- Aug 7th, 2010
1. When we kill any background processes database will be down.3. We can find corrupt block using v$database_block_corruption view using RMAN utility we can solve the problem recover block datafile...
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How can the problem be resolved if a SYSDBA, forgets his password for logging into enterprise manager?
mhans
- Feb 25th, 2008
1. Always you should have one more user activated as SYSDBA and this is achieved by using orapw utility2. If there is just one SYS user then on unix platform, login as ORACLE user (DBA group)3. sqlplus '/ as sysdba'alter user sys identified by 'xyz' ;This would change SYS pwd
senthilora
- Sep 24th, 2007
I think there are 2 ways to do that.1. Login as SYSTEM and change the SYS password by using ALTER USER.2. Recreate the password file using orapwd and set remote_password_file=exclusive and then restart the instance.
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What is directory naming in oracle9i ?
pradeesh04
- Dec 7th, 2007
Oracle Net Services use a centralized directory server as one of the primary methods for storage of connect identifiers. Clients configured directory usage can use the connect identifiers in the...
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What is the difference between Pctused and PctFree?
dinesh1909
- Nov 19th, 2007
Consider 8K block size. The total bytes 8 x 1024 = 8196 bytesEach block requires approximately 117 bytes for the header. Please note that the header size varies depending upon the block size. The tota...
C.Ramesh
- Nov 16th, 2007
PCT USERD - The Percentage of Minimum space user for insertion of New Row data. The value determines when the block gets into the FREELISTS structurePCTFREE - The Percentage of Space reserved for future updation of existing dataC.Ramesh
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Physical and Logical Backup
What kind of backup you take Physical / Logical? Which one is better and Why?
mselva84
- Feb 22nd, 2010
Logical Backups: In this backup Oracle Export utility stores data in Binary file at OS level.Physical Backups: In this backup physically Datafiles are copied from one location to another( Disk, Tape etc.)
bishma
- Aug 30th, 2008
Logical backup means backing up the individual database objects such as tables, views , indexes.. using the utility called EXPORT, provided by Oracle. The objects exported in this way can be imported ...
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Determine Number of Blocks Corrupted
You have a database. You have a datafile and some blocks are corrupted in the datafile. What statement will you issue to know how many blocks are corrupted?
kunal1017
- Apr 1st, 2008
you can use the DBVERIFY utility to check the corruption in datafiles so that you can now number of blocks corrupted.Here is the procedure :On o/s prompt login as oracle user : $ dbv file= &...
hemant.agarwal03
- Mar 12th, 2008
You can check the "V_$DATABASE_BLOCK_CORRUPTION" view to determine the corrupted blocks.
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Oracle Datafiles limit
How do you control No. of Datafiles one can have in an Oracle Database.
olilogu
- May 11th, 2009
At creation time you can set up the maximun numer of datafiles.CREATE DATABASE .....MAXDATAFILES 500If you want to check it:select * from V$CONTROLFILE_RECORD_SECTION where type ='DATAFILE';If you want to increase it, you have to recreate control file.
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Difference between 9i OEM & 10G OEM.
Explain the differences between 9i OEM & 10G OEM along with new features that changes the way you do your daily job
dbashashi
- Dec 13th, 2010
Who said there is no OEM in 9i. OEM was there in 9i too.As far as difference is there... There are many enhancement in 10g OEM over 9i OEM. There are several tools such as AWR and ADDM has been incorporated and there is Sql Tuning advisor too.RegardsShashi singh
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Recover corrupted database
If the entire disk is corrupted how will you recover the database and what are the steps to recover the database?
m4k4v3l1
- Jul 1st, 2009
Things Useful For Complete Recovery :1- Last Valid Backup2- Dump Files3- Archive Logs- If You Have a Valid Backup on Another Disk Rather Than The Damaged One , You Can Recover The Database till The Ti...
kalpeshbanokar
- Jul 24th, 2008
Succesful backup is possible iff there is "Archive Mode" is on.that is database is in Archive Mode.and if it's offthen there are only 99.9% chancesthroughGroup1 or Group2 of Online Redo log files.
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Resize Tablespaces
Is it possible to resize tablespaces and data files? If yes, how?
nafees
- Jul 22nd, 2008
Hi all,Yes i agree with the answer but resize in the sense,the size should also get decrease.we can decrease even the size of the datafile but the condition is the datafile should be empty.
rajendra_thanekar
- Jun 25th, 2008
hi,We can resize the datafiles which in turn resize the tablespace for which the datafile belongs. The command is alter database datafile '<datafile_name>' resize(size)M;By this co...
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Common problems while taking Backups
What are the common problems while taking backups? What are the necessary steps to take backup on to tapes and disks in real time?
sundarasaravanan
- May 4th, 2012
For a cold backup :shutdown oracle first and then proceed the cold(offline) back up. once you shutdown the oracle database insert the external tape/disk.pls ensure the tape/disk is in good condition. ...
doc123
- Mar 23rd, 2012
Some Common issues with Backup. If you are taking backup from no-archive log: then your database doesn't bring down due to some processes are running. If you are taking hot backup then may be newly ...
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Identify Datafile in Backkup Mode
When you execute: alter tablespace begin backup; How can Oracle engine can identify that the corresponding datafiles are in backupmode?
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Corrupted Rollback Segment
How will you rectify if one of the rollback segments gets corrupted
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Database hangs during Package Compile
When the developer trying to compile the package. But the database gets hanged? What will you check?
gogune
- Mar 31st, 2010
Deadlock could have occured. Check whether same object is updated by two sessions.
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How to convert local management tablespace to dictionary managed tablespace
amit19821
- Mar 13th, 2009
Local to Dictionary managed tablespcaes:exec dbms_space_admin.Tablespace_Migrate_FROM_Local('tablespace');Dictionary to locally managed tablespaces:exec dbms_space_admin.Tablespace_Migrate_to_Local('tablespace');
g.mrunalini
- Jul 22nd, 2008
Use the following package>execute dbms_space_admin.tablespace_convert_to_local('tablespace_name');>execute dbms_space_admin.tablespace_convert_from_local('tablespace_name');
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Difference between logical and physical Data
What is difference between logical & physical data and what do mean by physical & logical backup of data ?
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What is the difference between view and materialised view?
hanuman
- Sep 4th, 2012
View does not consume space and materialized view consume space
manoj100
- Aug 26th, 2012
A view is a simple select statement executed each time user runs query against it A materialized view is a physical persistent object used for performance improvement of summary data or replication. ...
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ORACLE 11g Architecture
What is the difference in Oracle 10g and 11g Architecture
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Database Connection TNS Names
User failed to connect database due to tnsnames, what activity you are going to do?
Oracle DBA Interview Questions
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