Query - Performance plzz help

Question

Hi All,
I would like to tune the following query in a better manner
SELECT hou.NAME organization_name
       ,haou.name parent_org_name
       ,msi.secondary_inventory_name sub_inventory_code
       ,msi.availability_type nettable_sub_inventory
       ,msib.segment1 item_name
       ,msib.description item_description
       ,mc.concatenated_segments category_name    
       ,msib.primary_uom_code item_uom_code
       ,XXTEST_TEST_ONHAND(msib.organization_id,msib.inventory_item_id,msi.secondary_inventory_name) AVAILABLE_ONHAND
       ,NVL((SELECT SUM(quantity_shipped - quantity_received)
             FROM rcv_shipment_lines rmlv
             WHERE rmlv.to_organization_id = msib.organization_id
               AND rmlv.item_id = msib.inventory_item_id
               AND rmlv.to_subinventory = msi.secondary_inventory_name
               AND source_document_code IN ('REQ','INVENTORY')
               AND rmlv.shipment_line_status_code in ('PARTIALLY RECEIVED','EXPECTED')),0) intransit_qunatity
       ,msib.organization_id
       ,msib.inventory_item_id 
       ,mic.category_set_id    
FROM mtl_system_items_b msib
     ,hr_organization_units hou
     ,mtl_secondary_inventories msi
     ,mtl_item_categories mic
     ,mtl_categories_b_kfv mc 
     ,per_org_structure_versions posv
     ,per_org_structure_elements pose
     ,hr_all_organization_units haou
     ,per_organization_structures pos
WHERE hou.organization_id = msi.organization_id
  AND msib.organization_id = hou.organization_id
  AND mic.inventory_item_id = msib.inventory_item_id
  AND mic.organization_id = msib.organization_id
  AND mc.category_id = mic.category_id
  AND mic.category_set_id = FND_PROFILE.VALUE('XXTEST_INV_INVENTORY_CAT_SET')
  AND pos.organization_structure_id = posv.organization_structure_id
  AND posv.org_structure_version_id = pose.org_structure_version_id
  AND haou.organization_id = pose.organization_id_parent
  AND pos.name = FND_PROFILE.VALUE('XXTEST_INV_ORG_HIERARCHY')
  AND pose.organization_id_child = msib.organization_id;  Purpose :
Actually this is for creating form view , and the custom function is encapsulating a oracle apps API. We can also put the custom function in POST_QUERY of the form block. But I feel it is better to put in view itself. We are expecting that this query will fetch around 500,000 records.
Expected record count
mtl_system_items_b - less than 100,000 records
,hr_organization_units less than 1000 records
,mtl_secondary_inventories less than 1000 records
,mtl_item_categories - - less than 300,000 records
,mtl_categories_b_kfv - less than 100 records
,per_org_structure_versions less than 1000 records
,per_org_structure_elements hou less than 1000 records
,hr_all_organization_units less than 1000 records
,per_organization_structures less than 1000 records
Vesrion of DB
10.2.0.4.0

Answer 1

Aside from what others have said, your WHERE clause isn't doing much filtering mostly joining so I would guess (only a guess) that indexes wouldn't be used.
Also, you're doing two things in the SELECT that may hurt performance, a function call and another SELECT statement.
Can you turn that inline SELECT into an outer join in the main query? What does that function call do? Can you embed the logic into your statement? Otherwise it's going to get called 500,000 times.