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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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NoArchiveLog Mode
A Database is running in NoArchiveLog mode then which type of backups you can take?
mangeshchede
- Mar 21st, 2010
If your Databse is in No Archivelog Mode then you must take a Cold backup of your Database.
naveen_rc
- Aug 4th, 2009
If your database is in NOARCHIVELOG mode, then the only type of backups that you should perform are closed, consistent (COLD BACKUP), whole database backups. The files in this type of backup are all consistent and do not need recovery, so the online logs are also not required.
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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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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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How to grant complete database access to an user as read only...?
mangeshchede
- Mar 21st, 2010
By using following SQL Command you can grant read only privillege to your user on whole database.SQL > grant select any table to user_name;and dont grant any other privilege to that user.
rajendra_thanekar
- Apr 9th, 2008
Hi,You can put the entire database in read only mode.startup mountalter database open read only;
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Database Buffer Blocks
How many type of database buffer blocks are available? What are they?
shekar2130
- Jul 15th, 2010
There are 3 types of buffers present:1. Free buffer2. Pinned buffer,3. Dirty buffer
sharmme
- Feb 17th, 2010
Following are the types of Buffer blocks available.Pinned - Marked not to be released as per LRU algorithm. These are marked as required for further writes/changes/reads by transactions.Dirty - Change...
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How to recover the DB if we lost controlfile and we are not having backup also and the database is down...?
shekar2130
- Jul 15th, 2010
If we are loosing control file then we will take backup of control file from alertlog file.
rharijan
- Sep 2nd, 2009
If controlfile is lost we can go to the trace file in udump and there after we can create control file by copying the datafile and redologfile and paste in user managed backup by giving old location to a new new location and then try to recover the old one giving the reuse option.
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What happens if i kill a mandatory background processes?
krish_makkena
- Aug 4th, 2010
If we kill the mandatory background processes the db should be shutdown i.e, instance is terminated.
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What is Dedicated Server and Shared Server?
ianilreddy
- Aug 7th, 2010
Dedeicated server: For one user one server processsesShared server: Where multiple user and one server process. In shared server whenever user request, server hands over the request to dispatcher and...
sharmme
- Feb 17th, 2010
In a Dedicated server mode, listener spawns a dedicated server process for each user process where as in shared server mode, listener assigns a dispatcher to each user process from the available ...
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Power Failure
What is the effect on database at the time of total power failure when an UPDATE query is under execution in Oracle 9i?
ianilreddy
- Aug 7th, 2010
When database is restarted, SMON will perform instance reecoveryRoll forward commited transactionsRoll back uncommited transactions using undo information.
Ram Sangwan
- Jun 24th, 2009
When the power failure occurs while an update statement is running. When the database is restarted it does an automatic recovery, when it finds the update statements pending, it performs a rollback of the update statement.Regards-Ram
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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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Redo Log
If we are running in NOARCHIVELOG mode and my all redo log files are full and data is still not committed by the current session. What activity will Oracle perform and what will happen with the un-comitted data?
ianilreddy
- Aug 7th, 2010
In database whatever changes we made that going to store in redologs. The changes are record in redolog buffer when certain conditions lgwr will write to redologs 1) When a transaction commit 2)&...
MAbdullah47
- Feb 5th, 2009
NONARCHIVE log will Protect the DB from Instence faliure but not from Media failure.The Redo files will be covered until the last backup taken , but after that all uncommited datae will be lost for the period (after the last backup) taken.
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TNS-03505: Failed to resolve name
HI I installed RHEL4 on my home pc.and I created 2 databases of oracle 10g (same vesrion)The problem is while iam establishing connectivity between these 2 databases iam getting error like TNS-03505: Failed to resolve namemy listerner.ora file isLISTENER=(DESCRIPTION_LIST = (DESCRIPTION = (ADDRESS_LIST= (ADDRESS=(PROTOCOL=IPC)(KEY=CHANDU)) (ADDRESS=(PROTOCOL=TCP)(HOST=127.0.0.1)(PORT=1521))...
mb.appsdba
- Sep 2nd, 2010
The issue usually occurs when the tns entiries we provide has some unwanted characters or spaces etc.Please also check the tns entry(alias) is pointing to the correct database with sid,hostname etc.If...
maniswamy
- Oct 3rd, 2009
Just check your port number if two database are in one PC the port number is changed.
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Where should you place Archive logfiles, in the same disk where DB is or another disk ?
poojap
- Oct 6th, 2010
Yes, Archive log files should be on different disk?because?in case of database failure we can get ?the data from the Archive logfiles.
dhs01
- Apr 15th, 2009
In addition to the previously stated reason that if there is a disk problem, not having them on that disk is a good idea, another issue might be contention. Putting them on the same disk would keep th...
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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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Control Number of Datafiles
How do you control number of Datafiles one can have in an Oracle Database?
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Database Connections
How will you determine the number of connections connected to your database?
Anupama Kanakam
- May 29th, 2011
We can also see these connections on Activity monitor. But you need permissions to see it.
jsavarin
- Nov 8th, 2010
We can determine the number of connections by using this - SELECT COUNT(*) FROM v$session;
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How do you sort a table?
dineshctbm
- Jul 2nd, 2011
Order By is a keyword which is using for sort the table records either ascending or desending.For eg,for ascending,Select emp_name,emp_identity from emp order by emp_identity;Select emp_name...
nalinicisf
- May 19th, 2008
contents or data of the table can be sorted by using clause ORDER BY in SELECT statement.By default the table is in ASCENDING order.SYN: SELECT * from [table name] &...
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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 -
Kill Multiple sessions
If have 50 inactive session and i want to to kill all session at once tell me the procedure to kill all 50 session at once
muthu5047
- Sep 3rd, 2011
in our project to kill all the inactive session we use the following script.. run the sql script given below it will give u all inactive sessions sid and serial no and redirect output to (inactive_kil...
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