ORACLE APPS DBA QUERY

                                                      Query to find Database Size

SELECT sum(bytes)/1024/1024 data_size FROM dba_data_files;

Query to get the size of all TEMP files:

SELECT nvl(sum(bytes),0)/1024/1024 temp_size FROM dba_temp_files;

Query to find space used by a database user.

SELECT sum(bytes)/1024/1024 user_size FROM user_segments;

Query to find the space occupied by all the users in a database.

SELECT owner, sum(bytes)/1024/1024 total_size FROM dba_segments

GROUP BY owner ORDER BY total_size DESC;

Total space occupied by all users:

SELECT sum(bytes)/1024/1024 total_size FROM dba_segments; 

Query to find free space in temporary tablesapce:

SELECT tablespace_name,SUM(bytes_used),SUM(bytes_free) FROM 

V$temp_space_header GROUP BY tablespace_name; 

Script to find Table size in a database.

select sum(BYTES/1024/1024) as TOTAL_GIG from user_segments where

SEGMENT_NAME = 'TABLE_NAME';

CONCURRENT MANAGER

1: What is concurrent manager?
Ans:
When an Oracle Applications user submits a request to run a program, it's called concurrent request. Concurrent manager are the programs, which are responsible for running the concurrent requests. When a user submits a report to be run as a concurrent request, the job enters in a request queue. Concurrent managers continously read request from this master queue and run the requests based on the request's schedule, priority, and compatibility rules. Concurrent managers run in background and they take care of initiating and completing the concurrent requests.

2: What are the different types of concurrent manager?
Ans:
Oracle Applications consist of several types of concurrent managers. The important ones are internal manager, standard manager and conflict resolution manager. Apart from these, you can define your own custom concurrent manager.
3: What is an internal concurrent manager?
Ans:
The internal manager is the one which is responsible for controlling all other concurrent managers. Its main task is to ensure that all other concurrent managers are up and running. The internal concurrent manager starts, sets the number of active processes, monitors and terminates all other concurrent processes through requests made to the service manager, including restarting and failed processes. The internal concurrent manager also starts and stops, and restarts the service manager for each node.
4: What is conflict resolution manager?
Ans:
The conflict resolution manager takes care of resolving the program incompatibilities and checks if a request in queue can be run in parallel with the running request. It also takes care of resolving the program incompatibilities. If a program is identified as run alone, then the conflict resolution manager prevents the concurrent managers from starting other programs in the same conflict domain.
When a program lists other programs as being incompatible with it, the conflict resolution manager prevents the program from starting until any incompatible programs in the same domain have completed running.
5: What is a standard manager?
Ans:
The standard manager is the master concurrent manager. This manager is always running and it can take care of processing any concurrent request. It has no specialization rules. This manager runs 24 hours a day for the whole year. The definition of this manager should never be altered. In case if you alter the definition of the standard manager and you have not defined additional managers to run your requests, some of the programs may not run in a proper way.
6: How do I enable/disable the conflict resolution manager?
Ans:
This is a system profile option "Concurrent: Use ICM". The default value of this profile option is No which allows the conflict resolution manager to be started. Setting the same to Yes will cause the conflict resolution manager to be shutdown and the internal concurrent manager will take care of the conflict resolution duties. Using the internal concurrent manager to resolve the conflicts is not recommended.
7: What are the different ways to stop concurrent manager?
Ans:
Concurrent manager can be stopped using the script adcmctl.sh. It can also be stopped using the Concsub utility. From the operating system, the concurrent manager can be stopped by querying the FNDLIBR process and killing the same.
8: What are the different ways to start concurrent manager?
Ans:
Concurrent manager can be started using the script adcmctl.sh located at the locations of the scripts or with the startmgr utility located at $FND_TOP/bin.
9: In administer concurrent manager form there are two columns labelled as actual and target. What are these columns and what is the thier significance?
Ans:
Target column lists the number of processes that should be running for each manager for this particular workshift. Actual column lists the number of processes that are actually running. If the actual column is zero, there are no processes running for this manager. If the target column is zero, then either a workshift has not been assigned to this manager, or the current workshift does not specify any target processes. If the target column is not zero, then the manager processes have either failed to start up, or has gone down.
10: How do I run/schedule a concurrent request from operating system level without logging into the applications?
Ans:
A concurrent request can be scheduled/run from the operating system using the CONCSUB utility. CONCSUB means Concurrent Submit.

ORACLE FOR US

Oracle Corporation is an American multinational computer technology corporation that specializes in developing and marketing computer hardware systems and enterprise software products – particularly database management systems

 we can make a successful and great career in the field of the oracle i m providing few things about the oracle.

There types of Oracle Certification we can do.
1. Oracle DBA
2. Oracle Developer
3. Oracle Application DBA

1. Oracle DBA
The person which maintain Oracle Database called Oracle Database Administrator.
There are some frequent work for Oracle DBA
1. Database Backup Responsibity.
2. Database Performance Tunning
3. Database Basic Administration Like " user creation, database security"
Above work is complete dedicated to Oracle DBA and every company which use Oracle Database they always need Oracle DBA.

2. Oracle Developer
The person which create coding and design forms and report for front-end application
There are some frequent work for Oracle Developer
1. Coding 
2. Create and Design Forms and Reports
3. SQL Tunning
Above work is complete dedicated to Oracle Developer

3. Oracle Application DBA

The Person which work on ERP (enterprise resource planning)
There are some frequent work for Oracle Application DBA
1. Implement Oracle ERP according company requirement.
2. Patching and Clonning
3. Maintain Application Module like "financial,hr etc"