OTL Time card query

SELECT --distinct
papf.EMPLOYEE_NUMBER,
papf.FULL_NAME EMPLOYEE_NAME,
to_char(htb1.start_time,'DD-MON-RRRR') START_DATE,
papa.segment1 PROJECT,
pt.TASK_number "Task",
hta.attribute3 "Type",
htb2.measure "Hours",
hts.approval_status "Status"
             FROM hxc_time_building_blocks htb,
                  hxc_time_building_blocks htb1,
                  hxc_time_building_blocks htb2,
                  hxc_time_attribute_usages htau,
                  hxc_time_attributes hta,
                  pa_projects_all papa,
                  hxc_timecard_summary hts,
                  pa_tasks pt,
                  per_all_people_f papf
            WHERE htb1.parent_building_block_id = htb.time_building_block_id
              AND htb1.parent_building_block_ovn = htb.object_version_number
 and HTB.SCOPE  = 'TIMECARD'
              AND htb.date_to = hr_general.end_of_time
              AND htb1.date_to = hr_general.end_of_time
              AND htb2.parent_building_block_id = htb1.time_building_block_id
              AND htb2.parent_building_block_ovn = htb1.object_version_number
              AND htb2.date_to = hr_general.end_of_time
              AND htau.time_building_block_id = htb2.time_building_block_id
              AND htau.time_building_block_ovn = htb2.object_version_number
              AND htau.time_attribute_id = hta.time_attribute_id
              AND papa.project_id = hta.attribute1
              AND hts.start_time = htb.start_time
              AND hts.resource_id = htb.resource_id
              AND papf.person_id = htb.resource_id
              AND papf.EMPLOYEE_NUMBER= nvl(:P_EMPLOYEE_NUMBER,papf.EMPLOYEE_NUMBER)
 and htb1.start_time between papf.effective_start_date and papf.effective_end_Date
              AND ((to_date(TO_CHAR(htb1.start_time ,'dd-mon-rrrr') ,'dd-mon-rrrr') >= to_date(:P_FM_DT,'dd-mon-rrrr') or :P_FM_DT is null)
              AND (to_date(TO_CHAR(htb1.start_time ,'dd-mon-rrrr') ,'dd-mon-rrrr') <= to_date(:P_TO_DT,'dd-mon-rrrr') or :P_TO_DT is null))
              AND hts.approval_status =nvl(:P_STATUS,hts.approval_status)
     AND papa.segment1 =nvl(:P_PROJECT_NO,papa.segment1)
              AND hta.attribute_category = 'PROJECTS'
              AND hta.attribute2 = pt.task_id
              AND hta.attribute1 = pt.project_id
 and exists (select 1 from HXC_TIME_ATTRIBUTE_USAGES HTAU2,HXC_TIME_ATTRIBUTES HTA2
              where HTAU2.TIME_ATTRIBUTE_ID = HTA2.TIME_ATTRIBUTE_ID
              and HTAU2.TIME_BUILDING_BLOCK_ID = HTB2.TIME_BUILDING_BLOCK_ID
              and HTA2.ATTRIBUTE_CATEGORY = 'SECURITY'
              and HTA2.attribute1 = to_char(FND_GLOBAL.ORG_id)