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How do you search for Index name in Oracle ?
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How can you check which user has which Role.
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Full Table Scan
There are about a 10,000 records in a table. A user 1 runs a query which is doing a full table scan. While doing the full table scan, user 2 changes some value x to y using a DML statement in record. What does the the 1st user see ( x or y ) ? If x, then where is the value stored?
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Search Method
If the large table contains thousands of records and the application is accessing 35% of the table which method to use: index searching or full table scan?
SSR
- Jul 20th, 2011
Depends on cardinality, for low cardinality then full scan better
prashanthpadal
- Mar 23rd, 2011
If the query has to get the output more than 5% of the full table then full scan is better than Index scan. Here is the matter of 35% then, it should go though full table scan.
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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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Change parameter in pfile
how to change the log_archive_format parameter in pfile if corresponding issys_modifiable parameter is "FALSE"
give me the full step by step procedure.
Thanks
Gyan -
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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$database_block_corruption view using RMAN utility we can solve the problem recover block datafile...
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How can be determine the size of the log files.
Query v$log
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Oracle Dead Locks
If dead lock happened for 2 applications at a time in a banking sector..how to resolve this issues without forcing any one of the application ..we should not have to stop the transaction...
Dharma Kotha
- Oct 10th, 2011
A deadlock occurs when data was locked simultaneously by two sessions(users) and waiting for data, this can be resolved by rollback statement.
dharma
- Aug 23rd, 2011
Dead Locks can be resolved by rollback statement.
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Stacktrace Server Error Log
What should you do when you find a stacktrace in the server errorlog?
Lokesh M
- Dec 7th, 2011
When the server crashes, it generates core dump. If value of orclsdumpflag is set to 0, then the server will also attempt to leave a stack trace. The location for the stack trace is: ORACLE_INSTANC...
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What is a datafile
csanthoshreddy
- Mar 6th, 2012
Datafile is the physical storage location of the database.tablespace is logical.for creation of tablespace one or more datafiles needed.we can define the datafile location with the following parameter
db_create_file_destDharma Kotha
- Oct 10th, 2011
Datafiles are physical data location of oracle architecture. Table space contains no.of datafiles.
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Daily tasks for an oracle dba
What are key tasks for an oracle dba on daily basis?
doc123
- Mar 22nd, 2012
Daily Tasks of DBA are following. 1. Disk Space checking for all databases, tablespaces, archive log destinations, dump destinations, and backup destinations. 2. All backup successfully finished or n...
Ankur Kaushik
- Mar 15th, 2012
1.Connectivity: Make sure each database is available and accessible both by logging in via user applications, as well as running test scripts. 2.Backups: Check database and log backups, archiving an...
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Locks in Oracle
A user issues the below query,
1. Select * from table1 lock table
At the same time DBA is trying to modify this table table1 using alter command, will he able to do that or not?doc123
- Mar 22nd, 2012
DDL lock are exclusive locks. It shared the data. Means anyone can select data from same table.
anil
- Mar 13th, 2012
There dba can break the lock given to table.
but in real time, no dba has the right to break the lock given by the user -
What are the components of logical database structure of Oracle database
doc123
- Mar 22nd, 2012
Logical Structure of Oracle is following.
Tablespace =>Schema => Segments => Extent => Oracle Block. (Remember Oracle block is smallest logical unit).csanthoshreddy
- Mar 6th, 2012
The logical components of database are tablespaces, segments, extents, datablocks. datablock is the smallest unit of oracle I/0.
Oracle DBA Interview Questions
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