Concurrent request running abnormally for very long time

Concurrent request running abnormally for very long time without completion:

1. Identified the long running query by taking trace of the concurrent request
2. Executed the tuning advisor for the problematic query using the following steps

Create Tuning Task:
===============
DECLARE
my_task_name VARCHAR2(30);
BEGIN
my_task_name := DBMS_SQLTUNE.CREATE_TUNING_TASK(
sql_id => '0j3dqg3a8aj8c',
scope => 'COMPREHENSIVE',
time_limit => 3600,
task_name => 'my_sql_tuning_task_1',
description => 'Tune query using sqlid');
end;
/

Execute Tuning Task:
===================
BEGIN
DBMS_SQLTUNE.EXECUTE_TUNING_TASK( task_name => 'my_sql_tuning_task_1');
end;
/


SET LONG 100000
SET LONGCHUNKSIZE 1000
SET LINESIZE 100
set pagesize 100

--***************************
--TO GET SUMMARY INFORMATION
--***************************

SELECT DBMS_SQLTUNE.REPORT_TUNING_TASK( 'my_sql_tuning_task_1') from DUAL;

--***************************
--TO GET DETAILED INFORMATION
--***************************
SELECT DBMS_SQLTUNE.REPORT_TUNING_TASK('my_sql_tuning_task_1','TEXT','ALL','ALL') FROM DUAL;