The maximum value of a maximum value without making two querys of the same

Question

Hi,
In the table cmp_lineas_cotizacion i need to take only rows with the maximum lc.mto_precio_venta of the maximum l.fec_ini_vigencia_costo of l.cod_producto, but I have the problem that cmp_lineas_cotizacion is a very load table with take to much resources of the database, I can't modify or agregate indexes, so I need a way to make this query more efficient. I want to find a way to replace the last 6 lines of this query and make it faster.
select b.segment1 || '.' || b.segment2 as ITEM,
        case when b.organization_id in (125,89,90,92,95,97,99,101,104,106,108,110,112,115,83,85,
                                                    87,88,91,93,94,96,98,100,102,103,107,109,111,113,114,116,
                                                    117,120,123,124,128,130,132,134,135,133,131,129,118,182)
                  then 1
             when b.organization_id in (105, 126)
                  then 2
        end as ZONE_ID,
        replace(l.mto_precio_venta,',','.') as STANDARD_RETAIL,
       'VEF' as STANDARD_RETAIL_CURRENCY,
        case when b.primary_unit_of_measure like '%KG%' then 'KG'
             when b.primary_unit_of_measure like '%Kg%' then 'KG'
             when b.primary_unit_of_measure like '%UND%' then 'EA'
             when b.primary_unit_of_measure = 'Kilogramo' then 'KG'
             when b.primary_unit_of_measure = 'Litro' then 'L'
             when b.primary_unit_of_measure = 'Unidad' then 'EA'
             else null
        end as STANDARD_UOM,
        case when l.Mto_precio_venta_cm_emp is not null then replace(l.Mto_precio_venta_cm_emp,',','.')
             else '0'
        end as SELLING_RETAIL,
        'VEF' as SELLING_RETAIL_CURRENCY,
         case   when b.PRIMARY_UNIT_OF_MEASURE like '%Barril%' then 'BA'
                when b.PRIMARY_UNIT_OF_MEASURE like '%Bolsa%' then 'KG'
                when b.PRIMARY_UNIT_OF_MEASURE like '%Bulto%' then 'BE'
                when b.PRIMARY_UNIT_OF_MEASURE like '%Caja%' then 'CS'
                when b.PRIMARY_UNIT_OF_MEASURE like '%Docena%' then 'CS'
                when b.PRIMARY_UNIT_OF_MEASURE like '%Kg%' then 'CS'
                when b.PRIMARY_UNIT_OF_MEASURE like '%Kilogramo%' then 'CS'
                when b.PRIMARY_UNIT_OF_MEASURE like '%Litro%' then 'Po'
                when b.PRIMARY_UNIT_OF_MEASURE like '%Paquete%' then 'PACK'
                when b.PRIMARY_UNIT_OF_MEASURE like '%Unidad%' then 'CS'
                else 'CS'
        end as SELLING_UOM,
        null as MULTI_UNITS,
        null as MULTI_UNIT_RETAIL,
        null as MULTI_UNIT_RETAIL_CURRENCY,
        null as MULTI_SELLING_UOM,
        null as LOCK_VERSION
from cmp_lineas_cotizacion l,
     inv.mtl_system_items_b b
where b.segment1 || '.' || b.segment2 = l.cod_producto
      and (l.cod_producto in ((select codigo
                             from tmp.viveres_vegetales)
                             UNION
                             (select codigo
                             from tmp.genericos)
                             UNION
                             (select codigo
                             from tmp.hijos_genericos)))
and l.fec_ini_vigencia_precio > to_date('01/09/2008','DD/MM/YYYY')
      and (b.segment1 || '.' || b.segment2, l.fec_ini_vigencia_costo, l.mto_precio_venta) in
                      select lc.cod_producto, max(lc.fec_ini_vigencia_costo), max(lc.mto_precio_venta)
                      from  cmp_lineas_cotizacion lc
                      where lc.fec_ini_vigencia_precio > to_date('01/09/2008','DD/MM/YYYY')
                      group by lc.cod_producto
                      )

Answer 1

Without table definitions, input data, and expected output, it's hard to test. But I would expect that analytic functions would be what you're after (assuming that omitting the "l.cod_producto in" clause from your main query in the subquery where you are getting the MAX values doesn't change any results). Something like
SELECT <<all your columns>>,
       l.fec_ini_vigencia_costo,
       l.mto_precio_venta,
       max(l.fec_ini_vigencia_costo) over (partition by l.cod_producto) max_vigencia_costo,
       max(l.mto_precio_venta) over (partition by l.cod_producto) max_precio_venta
  FROM <<the rest of your query>>will include the MAX values and the current row values without needing to hit the table a second time. Then you should be able to do
SELECT <<list of columns>>
  FROM (<<whole query from the last step>>)
WHERE fec_ini_vigencia_costo = max_vigencia_costo
   AND mto_precio_venta = max_precio_ventaJustin