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Is it possible to disable the connection sys as sysdba. If yes, does violates oracle 9i?
kashyap_aseem
- Feb 14th, 2008
In 10g there is a option to lock an acount we can lock system user through this correct me if i am wrong
Ritesh Raj Singh
- Jul 12th, 2006
There is no possibilities of disabling the connection as sysdba because sys is the owner of the database who has all the powers of the database so you can disable the account of sys what u can do is y...
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How do you create a primary key to existing table with duplicate records?
hemant.agarwal03
- Mar 17th, 2008
Alter table add constraint primary key ()DEFERRABLE initially immediate enable novalidate
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How to provide much and more security to my users in the database?
rajendra_thanekar
- Apr 9th, 2008
Hi,create role in database with proper permission. then assign that role to the user. This is the simplest method to implement secuirty in database.
Yogesh
- Feb 6th, 2007
By providing proper Grants on tables such a (select ,update delete..) to different user a DBA can have a better control over his database and if he finds some problem he can Revoke the given rights of the specified user.
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What is the difference between a system crash and a media failure?
dbashashi
- May 20th, 2008
In simple terminology, combination of S/w(Operating system et all) and hardware(Disk Drives) on which these S/W(OS) are loaded, are vital for smooth runing of system. Failure of any of ...
stepwil
- Apr 16th, 2008
A system crash is when an operating system or an application fails corrupting or deleting database objects or the database itself. Media failure is when the hardware that houses the database fails ie: hard disk failure.
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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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Oracle server down time
what are the necessary steps to be take when server gets down? How can we increase size of a database?
subha gunasekaran
- Jun 5th, 2008
1.Bring up the server. 2.Run the profile of the database 3.Bring up the database. 4.In server prompt, check ps- ef | grep pmon - This is used to check whether the database is up or not. 5.Bring u...
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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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When normalizing a table that can have a many to many relationship with another table, what steps should you take?
Looking for a detailed answer if possible
aw_zahid
- Nov 18th, 2008
A many-to-many relationship is usually resolved by making a tertiary (third intermediate) table where PKs of both the related tables are recoreded as FKs.Example: A student can take many classes and a...
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How would you pass hints to the SQL processor?
dhampack
- Nov 24th, 2008
I would say, write more sql statementfor exin join statement if x=y, y=z (you can also add x=z to give more hint to optimizer)
LAKSHMAN CHOWDARY
- Oct 17th, 2005
USING COMMENT LINES WITH (+) SIGN YOU CAN PASS THE HINTS TO SQL ENGINE----------->/* +PARALLEL() */
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Different types of table join.
dhampack
- Nov 24th, 2008
In Sybase(T-SQL), there are 3 types of joins1) Equi Join2) Natural Join3) Outer Join (left & right)Joins based on equality (=) are called equijoins. Equijoins compare the values in the columns bei...
Bobby
- Sep 14th, 2006
There are 3 types of joins basis on Oracle 8i Simple join ?????1. Equi join : Equi join is one which contains comparision operator '=' in where clause. ?????2. Non Equi join: If the com...
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What is BITMAP index and B-Tree Index in Oracle 10g
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raja_wipro
- Dec 2nd, 2008
In Oracle 10G we do not have Bitmap Index . Bitmap index is available only in Oracle9i Enterprise Edition
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High Water Mark
What is High Water Mark in Oracle?
DPsireesha
- Feb 24th, 2009
The High Watermark is the maximum fill-grade a table has ever reached. The blocks above high water mark are empty blocks.Initially when you create a table the high water mark is the first block. When ...
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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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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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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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How can you find all the tables created by an user?
bapiora
- Jun 29th, 2009
As?a dba if you want such info. from your database side.You issue following command from server end.?? select owner,table_name,tablespace_name from dba_tables or if you need some specific user info. issue?? select owner, table_name ,tablespace_name from dba_tables where owner='< username>'
subha gunasekaran
- Jun 5th, 2008
select sum(bytes)/1024 from dba_segments where segment_name='TABLE_NAME' and owner=' 'As segment_name represents table_name,index_name..provide the table_name and index_name in the above query
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Why data reshuffling is required?
saurabh.nigam27
- Sep 16th, 2009
Due to DML commands, HWM will increase, which means for a query till the HWM all the blocks will be read whether blocks contain data or not (due to delete), because of this performance will go down.
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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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Reading Oracle Control file content
Can we read Control file? If yes, then how?
lakshmi143.e
- Oct 14th, 2009
SQL> ALTER DATABASE BACKUP controlfile TO trace;
You can find the trace file which is backup of control file in udump directory.
narendra05
- Oct 2nd, 2009
Control file is the metadata of data and the information is stored in binary format. Some part of the control file can be seen by tracing it to trace (struncture of database can be seen by tracing th...
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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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