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Recover Database
There are 100 datafiles, numbered from 1 to 100. File number 10 is deleted and it has 500 MB of data. The database is working in No-Archive log mode. How can the database be recovered?
vijaykaushik
- Dec 31st, 2008
This can be easily done but you will loose the data if you don't restore from backup.If you have a backup of datafiles and controlfile then restore them.If you don't have the backup then you n...
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Load Data into Multiple Tables
How to load data into multiple tables at once?
vijaykaushik
- Dec 31st, 2008
You can use SQL loader to do this. Using the When condition in SQL Loader control file this is possible.
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Replication Server
Explain how will you setup Replication Server & sync it?
vijaykaushik
- Dec 31st, 2008
Replication server can be setup using many ways1)Using Oracle Streams2)Using Advanced replication 3)Using Mviews.Each has their own mechanism to sync data. Regards,Vijay Kaushik
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How to handle data curreption for ASM type files?
imran44
- Dec 30th, 2008
The storage array should contain one or more spare disks (often called hot spares). When a physical disk starts to report errors to the monitoring infrastructure, or fails suddenly, the firmware should immediately restore fault tolerance by mirroring the contents of the failed disk onto a spare disk
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When a database is started, Which file is accessed first?
raghukiranreddy
- Aug 19th, 2008
you want to starting up a database by using STARTUP command....SQL>STARTUPto start instance, database must read the intialization parameter from either a server parameter file(SPFILE)or a trad...
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Increase %LIKE Operator Performance
How do you increase the performance of %LIKE operator?
ravinder.pathania
- Oct 6th, 2008
The wildcard char % can be placed in one of three ways: %searchwordhere% searchwordhere% %searchwordhere The searchwordhere% is the fastest because it can use an index if one is specified on that ...
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Oracle Reserved Memory and Unreserved Memory
What is Oracle Reserved Memory and Unreserved Memory? What is the size of Oracle Reserved Memory?
bassem_farouk
- Sep 21st, 2008
Is the meomory that is allocated to each connection to Oracle, this memory is not recliamed even if the session is inactiveit is recliamed if the session is disconnected onlyto see it:D:appadminproduc...
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Remove Oracle memory segments
How do you remove memory segments
bassem_farouk
- Sep 18th, 2008
To see the Oracle memory segments from UNIX write ipcsthen look at the status column, the one with status is empty and? owner is oraclewrite down the shmid, ex: 2 find 2 shmid 123 and 456?in order t...
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Tablespace Quota
A user has connect and resource privileges allocated by the DBA. He is been allocated quota on three tablespaces by the DBA - Default Tablespace Quota 500 M - Tablespace 1 Quota 100 M - Tablespace 2 Quota 200 M Now the user tries to make a table which uses 300 M in tablespace 2. Will he be successful?
bassem_farouk
- Sep 17th, 2008
Yes he will be successful. because resource role grant user unlimited tablespace system privilege. quota ignored. SQL> create user test identified by test1; User created. SQL> grant connect, reso...
vishnusivathej
- Jul 21st, 2008
There will be no such thing as default size for a tablespace u have to assign it when it is being created.. and more over by default u can have 100 datafiles in a database which is the default value used during the database creation process u can also change this value..
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Database Designing and Modeling
What are the differences between database designing and database modeling?
ramu541
- Sep 12th, 2008
Effective database design can help the development team reduce overall development time and costs. Undertaking the process of database design and creating a data model helps the team better understand...
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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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Cost Based Optimizer and Rule Based Optimizer
What is the difference between Cost Based Optimizer and Rule Based Optimizer?(CBO is the default optimizer)
ajay.ocp
- Aug 20th, 2008
In brief the rule-based method means that when executing a query the database must follow certain predefined rules and matter what data is stored in affected database tables. The cost-based method mea...
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Differentiate file using filename
Three users at a time giving the following command: alter database backup controlfile to trace; How can you differentiate the file using the filename itself?
baala
- Aug 11th, 2008
When you issue the command "alter database backup controlfile to trace ; " a trace file will be created in the user_dump destination.The default name of the trace file would look something similar to ...
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Export query question
exp userid=system/manager file=expfile.dmp log=expfile.log full=Y compress=Y buffer=1000000If i do't mention compress & buffer parameter , then this query will run/not.
nafees
- Aug 10th, 2008
Yes, exactly it will run perfectly because compress and buffer both are optional.
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Accessing Dual Table
Explain Dual table. Is any data internally stored in dual table. Lot of users are accessing select sysdate from dual and they getting some millisecond differences. If we execute SELECT SYSDATE FROM EMP; what error will we get. Why?
abdulraheem_ar
- Aug 5th, 2008
Dual is a system owned table created during database creation. Dual table consist of a single column and a single row with value xWe will not get any error if we execute select sysdate from scott.emp?...
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Scenarios for rebuilding indexes
What are the different scenarios for rebuilding indexes...
chandubtech
- Aug 2nd, 2008
Actually you need to rebuild the indexes for 2 main scenarios.1)deleted entries represents 20% or more of the current entries2)the index depth is more than 4 levelsOracle index nodes are not deleted p...
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What are the characteristics of data files
srinivasanram2004
- Jul 29th, 2008
Characteristics of a Data File : - A Data file can be associated with only one tablespace. - Once created, a datafile can be increased or decreased in size with RESIZE command. Example: ALTER da...
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Physical Standby Database
Outline the steps required for physical standby database creation?
nafees
- Jul 21st, 2008
Hi all,IT IS POSSIBLE WITH THE HELP OF DATA GUARD.To create a physical standby database ,the standby databse should be in MRM(Managed recovery mode)Let we proceed with an example, let ...
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Import Export Utilities
How does one use the import/export utilities?
nafees
- Jul 22nd, 2008
Logical Backup using export utility works as an alternative backup method.we can export from one user and import into another within the same database.we can export from one database and import into a...
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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...
Oracle DBA Interview Questions
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