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What is a full table scan and what is the ideal rate/min for a FTS?
parthokonar1
- Sep 26th, 2007
FTS means the oracle server reads all the records from the concerned table. And it all depends on the size of the table/ partitioned table. What you say if a table consists of 10 million of records. so we musr avoid FTS. And after all Oracle is build for searching.
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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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What is the difference between DSS and OLPT
kodaliprakash
- Sep 7th, 2007
DSS is desicion support system. This is mainly useful for tking appropriate decisions based on existing data. All the data is already available in the DB. And we have to get reports according to the n...
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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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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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DBMS analysis and Requirements
Imagine that you joined a company as DBA and your first task is to create test and production database environments for application developers and users. How would you analyze requirements for a new DBMS? Write your answer according to the requirements of Oracle 9i or 10g Enterprise database system.
vdamodharan
- Jan 20th, 2010
That depends on what role you are playing in the DBA team. If you are a operation DBA, then all you need to know to create a database are: Initial sizing, redo, archive log size. The...
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What is an intelligent agent?
azam.irshad
- Jan 2nd, 2008
A process that runs on each of the nodes. It functions as the executor of jobs and events sent by the console by way of the mangement server. High availability is ensured since the agent can function regardless of the status of the cosole or network connections
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What is free list group?
azam.irshad
- Jan 2nd, 2008
Sets of free lists available for use by one or more instances.When data is frequently inserted into a table from multiple nodes and the table is not partitioned, use free list groups to avoid performa...
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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 to calculate the row length?
Lokesh M
- Dec 7th, 2011
You can make use of VSIZE function to get the number of bytes in the internal representation of individual field. However this cannot be applied on fields that has BLOB data type and in such case you have to use dbms_lob.getlength function on BLOB data type field.
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Database Status
How will you check the database status from os level in a unix env ?consider that some of the instances are in mount state; hence checking the pmon os process will be vain..? Need a unix os command to check if the databases are up and running
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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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Hard Disk Crash
What will happen in database if your like hard disk crashes & what will be your next step to recover that database?
mangeshchede
- Mar 21st, 2010
If your Harddisk gets crashed then If your Database is in Archive Log Mode, you should recover your database by applying all Archives or by restoring the latest backup.
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Recovery Catalog
How will you find out if your database is using recovery catalog or not?
ianilreddy
- Aug 7th, 2010
Using catalog database we can find if the database registered or not in recovery catalog database? SELECT * FROM rc_databaseWhere we can find all the registred databases;
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Alert Log File
What are contents that are not saved in alert log file? What happen when alert log file is full?
dbashashi
- Oct 8th, 2010
Almost all the event against the database which may hinder its smooth operation is captured in Alert Log file as error messages.Oracle creates a new alert log files if you delete the current one after taking backup for future reference.Shashi b Singh
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Alert log file
how to see some selected lines in alert log file in unix environment.
like tail -100f alert_SID.log we can see only 100 lines but i need to see the lines between 300 to 500 from down .muthu5047
- Sep 3rd, 2011
Assuming you need lines 20 to 40,
sed -n '20,40p' file_name
or
awk 'FNR>=20 && FNR
Database Admin Interview Questions
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