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Temp DB Full
What do you do when tempdb is full?
hari_97us
- Nov 26th, 2009
You need to clean up the space and add more space in order to prevent this error in future.
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What is the correct sequence among FETCH, EXECUTE, And PARSE
Vishal
- Sep 18th, 2007
1. Parse: a. Search for identical statementb. Check syntax, object names, and privilegesc. Lock objects used during parsed. Create and store execution plan2. Execute: Process the Statement3. Fetch: Return rows to User Process
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What are the types of synonyms
hmounir
- Dec 27th, 2009
1- a private synonym is defined in the schema of a user and is available only to the user.2- a public synonym is usually created by dba and is available for use by any database user.
praveena
- Sep 12th, 2005
Two types of synonims.1.public synonim,2.private synoniim.private synonym is confined to a particular user.public can be used by all the user's.
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Explain the relationship among database, tablespace and data file.What is schema
hmounir
- Dec 27th, 2009
The datafiles in an Oracle database are grouped together into one or more tablespaces. An Oracle tablespace consists of one or more datafiles; a datafile can be a part of one and only one tablespace.Schema can own any type of object in the database: Indexes, Sequences, Views, so forth.
imran44
- Jan 9th, 2009
The database is actually a collection of objects, which are made up of tablespaces and each tablespace must have datafile associate with it. The tablespace cannot be created without datafile. The tabl...
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What is hash cluster
hmounir
- Dec 30th, 2009
A special type of clusterd table, a hash cluster, operates much like a regular clusterd table, except that instead of using a cluster index, a hash cluster uses a hashing function to store and retrieve rows in a table.
soccer_champ
- Jun 20th, 2005
A hash cluster uses a hash algorithm, which could either be system generated or user defined, to calculate the location of a row, both for retreival and for DML.
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PCT Free
What is PCT Free and PCT Used?What is PCT increase parameter in segment?What is growth factor?
mkguduru
- Jan 21st, 2010
PCTFREE: Percentage of blocks to be reserved for future updates.After this parameter is met the block is considered to be full and it is not available to insert new rows. PCTUSED: It allows the block to reconsidered for the insertion of new rows.
refakat
- Aug 12th, 2009
This is the parameter which specify in percent? that a block can only used for insert or come in the freelist(list of blocks in segment ready for insert operation) when used space in a block is less ...
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What are the different types of segments
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Physical and Logical Backup
What kind of backup you take Physical / Logical? Which one is better and Why?
mselva84
- Feb 22nd, 2010
Logical Backups: In this backup Oracle Export utility stores data in Binary file at OS level.Physical Backups: In this backup physically Datafiles are copied from one location to another( Disk, Tape etc.)
bishma
- Aug 30th, 2008
Logical backup means backing up the individual database objects such as tables, views , indexes.. using the utility called EXPORT, provided by Oracle. The objects exported in this way can be imported ...
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What does database do during mounting process?
midhunam
- Mar 7th, 2010
When the startup command enters the mount stage, it opens and reads the control file. The control file is a binary file that tracks important database information, such as the location of the databa...
cmanne
- Jan 4th, 2006
During database mount process, Oracle would check for the existence of controlfiles mentioned in init.ora file but it wont check the contents of the controlfile which is done during the opening of database.
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What spfile/init.ora file parameter exists to force the CBO to make the execution path of a given statement use an index, even if the index scan may appear to be calculated as more costly?
Tirumal Devulapalli
- Feb 23rd, 2006
CBO (Cost Based Optimizer):Generates an execution plan for a SQL statementoptimizer_index_cost_adj parameter can be set to help CBO to decide an execution plan, which effects the speed of SQL query.we...
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Database hangs during Package Compile
When the developer trying to compile the package. But the database gets hanged? What will you check?
gogune
- Mar 31st, 2010
Deadlock could have occured. Check whether same object is updated by two sessions.
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Oracle Database Monitoring
If Several databases are up and running, which command will help to monitoring in os ?
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Corrupt Master Database
What do you do when the server cannot start due to a corrupt master database?
rahulniki
- May 9th, 2010
If the master database is corrupt, then surely others also do have the problems and thus the need of MDF recovery comes to an immediate. However you can try out to rebuild it with rebuild.exe and restore it.
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What is the most important action a DBA must perform after changing the database from NOARCHIVELOG TO ARCHIVELOG ?
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Tuning Indicators
What tuning indicators can one use?
prahlad_786
- Jun 25th, 2010
The following high-level tuning indicators can be used to establish if a database is performing optimally or not: • Buffer Cache Hit Ratio Formula: Hit Ratio = (Logical Reads - Physical Read...
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Why and how the deadlock situation arises
If one user is already updating the table and it has a lock, the other user cannot access the table to update. then why and how the deadlock situation arises ?please explain with example.
prahlad_786
- Jun 25th, 2010
When 2 different DML executed on the same resource then it leads to dead lock.Example:If a resource locked by user A and it also need resource which is locked by user B. B also need a ...
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What does a control file contains
gurbux
- Jul 18th, 2010
Control file contains structure and status of the database. It contains database name, datafile and redo log information, SCN number, timestamp of database creation, redo log sequence number.
ramesh khanna
- Jun 27th, 2005
Information about the database,redologfile and datafile,archivelog file location and current scn no and redo log file
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What is the use of redo log information
gurbux
- Jul 18th, 2010
Redo Log Files are used in case of database recovery. As redo logs contain all committed changes made to the data, they are applied from the time database crashes to recover database to point in time.
Amit
- May 7th, 2005
Redo log information are used to recover database if it get currept.
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Troubleshoot SQL * Plus
If the SQL * Plus hangs for a long time, what is the reason?
gurbux
- Jul 19th, 2010
SQL statement is taking long time to retrieve results from database.See which statement is taking longtime by running SELECT * FROM sqltext; or SELECT * from v$session_longops;
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Alert log files
What are four errors found in an alert (error) log that can ruin a DBA's appetite and how can you avoid them?
shaanahmed007
- Aug 3rd, 2010
If we are getting any issue regarding database while performing any activity we should check alert log file in dump destination.1) Snapshot too old error (O1555)2) Deadlock error3) Any issue regarding backup & recovery
brandedfundoo
- Jun 2nd, 2010
I agree..Deadlock error: Oracle takes care by itself. No damageSnapshot error: Rerun query. No damageOra-00600 : Internal.. very critical. Though directly Oracle has to be involved in resolution, stil...
Oracle DBA Interview Questions
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