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What is the default sort order in oracle?
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Fractured Block
What is mean by fractured block in terms of manual hot backup?
ganesh
- Mar 12th, 2013
In case of hot backup we get fractured blocks, because of this reason hot backups is called Inconsistent backup. let say in hot backups our operating system copies OS block by OS block while copy is g...
alok83
- Apr 11th, 2008
The concept of fractured block occrus when backup is under process.It means you are taking backup and some other session is updating it.Then backup process can not get the consistent image of the block and it will be inconsistent right thats why it is called fractured block.
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Logical online backup
Can you take online backup of a Control file if yes, how? Explain about Logical Backup?
bapiora
- Jun 29th, 2009
During database online you perform logical online backup for control file. ALTER DATABASE CONTROLFILE TO TRACE Through this command you perform? control file trace backup which is logical.
impalor
- Dec 9th, 2008
You could use alter database backup controlfile for a binary copy of control file.
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Where should you place Archive logfiles, in the same disk where DB is or another disk ?
poojap
- Oct 6th, 2010
Yes, Archive log files should be on different disk?because?in case of database failure we can get ?the data from the Archive logfiles.
dhs01
- Apr 15th, 2009
In addition to the previously stated reason that if there is a disk problem, not having them on that disk is a good idea, another issue might be contention. Putting them on the same disk would keep th...
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How is locking implemented?
Raghunathan Asari
- Jul 22nd, 2007
Whenever an SQL is issued for execution, DB2 checks for lock avoidance by checking the SQL.Eg. SELECT ...... WITH UR or BIND with ISOLATION (UR) (UR Uncommitted Read)If not DB2 checks&nbs...
Culver_lake
- Mar 19th, 2006
Locking in most modern database management systems is implemented implicitly. That is you never have to ask for a lock nor will you ever fail to release a lock. In DB2 this is all controll...
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Is it advisable to force an index when you want to select most of the entries in the table?
John Netherwood
- Nov 14th, 2007
No it isn't. If you are going to select most of the entries then you will have to read through the entire table anyway. Forcing the use of an index will just be an extra overhead.
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What is addressing modes? What is a node, How to insert into nodes?
kumar1974
- Jan 22nd, 2008
Dear Pooja your answer is correct. And please write the answer in steps wise or by paragraphs wise.Regardskumar
Pooja Chaturvedi
- Nov 19th, 2006
Addressing modes, a concept from computer science, are an aspect of the instruction set architecture in most central processing unit (CPU) designs. The various addressing modes that are defined in a g...
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How do you know that fragmentation is occurred and how do you fix it. ...?
subha gunasekaran
- Jun 5th, 2008
To see fragmentation:select sum(bytes)/1024 from dba_data_files where tablespace_name='';output: 10select sum(bytes)/1024 from dba_segments where tablespace_name='';ouput :...
sjpunshi
- Sep 25th, 2007
Query dba_segments, dba_free_space for the tablespace and table, if too many extents are avaiable, yet space availability is a problem, implies that the table is fragmented. Solution, export the segment. recreate and import, fragmentation is eliminated.
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Can RAC structures have different operating system nodes in cluster. e.g one node linux and other node is Windows. if not then why?
arulibra
- Jan 13th, 2010
No, you cant have different operating system in different nodes. All the nodes should be of same hardware, same OS, same version of cluster ware and RAC software. Even the oracle software and operatin...
parthokonar1
- Sep 26th, 2007
No it cannot be all the nodes have to be same os/platform. before oracle installation RAC software has to be installed. for load balancing etc
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Why minimum extents are required in roll back segment?
dbashashi
- May 20th, 2008
It is two. It is the minimum no of extents that we can assign to roll back segment.The max extents depends on the version of Oracle being used.
phani99_sakar
- Feb 19th, 2008
The minimum requirement for a DB or to start an instance it is mandatory to have atleast one roll back segment( if we or not ginving it oracle will take it from sys...) that is minimum.....and mandatory.............
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If you 100 table spaces so how to find which table space is growing and which one is volatile?
narendra05
- Oct 2nd, 2009
In 10g the AWR repository keeps track of data for 60 days by default and can store the information of tablespace growth for this period.Alternativey you can set the threshold in entreprise manager for a tablespace to respective which can trigger email alert if configered.
hemant.agarwal03
- Mar 17th, 2008
Select sum(bytes),TABLESPACE_NAME from dba_segments group by TABLESPACE_NAMEorder by sum(bytes) desc/
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Two Phase Locking Protocol
Explain the concept of two phase locking protocol with an example?
dhs01
- Apr 15th, 2009
Not sure of the particular terminology but 2 phase locking I believe would be similar to 2 phase commit where you must first make sure that everybody involved is ready, able, and willing (phase 1) then the next phase is when it actually happens (phase 2).
rpeters83
- Dec 9th, 2008
I'm no DB admin but I'll give it a shot. It's a protocol gauranteed to allow serialized actions on a database by having a locking phase and an unlocking phase. Meaning, during locking, no other transactions may be performed on the database until it is unlocked.
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Redo Log
If we are running in NOARCHIVELOG mode and my all redo log files are full and data is still not committed by the current session. What activity will Oracle perform and what will happen with the un-comitted data?
ianilreddy
- Aug 7th, 2010
In database whatever changes we made that going to store in redologs. The changes are record in redolog buffer when certain conditions lgwr will write to redologs 1) When a transaction commit 2)&...
MAbdullah47
- Feb 5th, 2009
NONARCHIVE log will Protect the DB from Instence faliure but not from Media failure.The Redo files will be covered until the last backup taken , but after that all uncommited datae will be lost for the period (after the last backup) taken.
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Target Database RMAN Backup
What are the steps required to enable the RMAN backup for a target database?
bapiora
- Jun 29th, 2009
Open a RMAN session and connect with target database, if you follow standalone command method just issue BACKUP DATABASE?command its allocates channel and do the backup, but if you follow batch comma...
anuradhad
- Feb 24th, 2009
Steps required for RMAN1)create a user to hold the recovery catalog2)Grant connect,resource,recovery_catalog_owner to the user3)Create recover catalog4)Register database.Each database to be backed up by RMAN must be registered
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Power Failure
What is the effect on database at the time of total power failure when an UPDATE query is under execution in Oracle 9i?
ianilreddy
- Aug 7th, 2010
When database is restarted, SMON will perform instance reecoveryRoll forward commited transactionsRoll back uncommited transactions using undo information.
Ram Sangwan
- Jun 24th, 2009
When the power failure occurs while an update statement is running. When the database is restarted it does an automatic recovery, when it finds the update statements pending, it performs a rollback of the update statement.Regards-Ram
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NoArchiveLog Mode
A Database is running in NoArchiveLog mode then which type of backups you can take?
mangeshchede
- Mar 21st, 2010
If your Databse is in No Archivelog Mode then you must take a Cold backup of your Database.
naveen_rc
- Aug 4th, 2009
If your database is in NOARCHIVELOG mode, then the only type of backups that you should perform are closed, consistent (COLD BACKUP), whole database backups. The files in this type of backup are all consistent and do not need recovery, so the online logs are also not required.
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