One of the important area of Concurrent Manager tuning is monitoring the space usage or the subsets within each concurrent manager. When the space in FND_CONCURRENT_PROCESSES and FND_CONCURRENT_REQUESTS exceed 50K, you can start to experience serious performance problems within your Oracle Applications.Oracle Applications.When you experience these space problems, a specific request called “Purge Concurrent Requests And/Or Manager Data” should be scheduled to run on a regular basis.This request to purge can be configured the request data from the FND tables as well as the log files and output files on accumulate on disk.

When the tables FND_CONCURRENT_REQUESTS and FND_CONCURRENT_PROCESSES reaches above 3000-4000 rows, the performance diminishes.You have to run Purge Concurrent Request and/or Manager Data program on a regular basis depending on the amount of request being run.
Note:In every 7 days or once in 15days we should run the Purge Concurrent Request and/or Manager Data program.

Find Size in KB for FND_CONCURRENT_REQUESTS :

sql> SELECT (BYTES/1024)/1024 “Size in KB” from dba_segments where SEGMENT_NAME=’FND_CONCURRENT_REQUESTS’;

O/P : Size in KB
———-
3.65

Sql> SELECT (BYTES/1024)/1024 “Size in KB” from dba_segments WHERE SEGMENT_NAME=’FND_CONCURRENT_PROCESSES’;

O/P : Size in KB
———-
10.75

How to Purge Concurrent Request and/or Manager Data?

Login to frontend with sysadmin responsibility:

Navigate :

System Administrator– > Concurrent –> Requests

Click on Submit a New Request — >Select Single Request click ok

Enter Name as Purge Concurrent Request and/or Manager Data

Entity – ALL / Request / Manager

ALL - Purges records from database tables that record history information for concurrent requests,concurrent managers, and purges request log files,manager log files , and report output files from the operating system.

Request - Purges records from database tables that record history information for concurrent requests,and purges request log files and report output files from the operating system.

Manager – Purges records from database tables that record history information for concurrent managers and purges manager log files from the operating system.

Mode - Age / Count
Age – Enter the number of days for which you want to save concurrent request history,log files, and report output files.The purge program deletes all records older (in days) than the number you enter.For example, if you enter “5″, then all concurrent request history,log files, and report output files older than five days is purged.

Count – Enter the number of (most recent) records for which you want to save concurrent request history,log file, and report output files.The purge program starts from the most recent records,retains the number you enter, and purges all remaining records.For example, if you enter “5″, then the five most recent concurrent request history records,request log files, manager log files,report output files are saved, and all remaining records are purged.

Mode Value – Value

Mode Value – Enter a value to define the number of days for Mode=Age or the number of records for Mode=Count. The valid values are 1 – 9999999.

Then Submit.

The database tables that are affected by running the Purge Concurrent Request and/or Manager Data program are:
FND_CONCURRENT_REQUESTS : This table contains a complete history of all concurrent requests.
FND_RUN_REQUESTS : When a user submits a report set, this table stores information about the reports in the report set and the parameter values for each report.
FND_CONC_REQUEST_ARGUMENTS : This table records arguments passed by the concurrent manager to each program it starts running.
FND_DUAL : This table records when requests do not update database tables.
FND_CONCURRENT_PROCESSES: This table records information about Oracle Applications and operating system processes.
FND_CONC_STAT_LIST : This table collects runtime performance statistics for concurrent requests.
FND_CONC_STAT_SUMMARY: This table contains the concurrent program performance statistics generated by the Purge Concurrent Request and/or Manager Data program. The Purge Concurrent Request and/or Manager Data program uses the data in FND_CONC_STAT_LIST to compute these statistics.