Request for tunning the query

Question

Hi,
Can anyone help me on the below query while improving performance. WHen i executed in TOAD 8.6.1 it is taking cost 8890. becoz of joins & some table are scanning fully eventhough there are some indexes on it.
If possible please rewrite the below query in anyotherway.
SELECT
SR.*,
frozen_quote.*,
WORKORDER.pscdate,
WORKORDER.ascdate,
WORKORDER.targstartdate,
WORKORDER.targcompdate,
WORKORDER.schedfinish,
WORKORDER.actfinish,
WORKORDER.estdur,
WORKORDER.wonum,
WORKORDER.MPRN,
WORKORDER.sihousename AS wositehousename,
WORKORDER.sihouseno AS wositehouseno,
WORKORDER.sistreet AS wositestreet,
WORKORDER.sicounty AS wositecounty,
WORKORDER.siposttown AS wositeposttown,
WORKORDER.sipostcode AS wositepostcode,
WORKORDER.workorderid
FROM (maximo.SR
INNER JOIN
(maximo.RELATEDRECORD
INNER JOIN maximo.WORKORDER
ON RELATEDRECORD.relatedreckey=(
CASE
WHEN WORKORDER.parent IS NOT NULL
THEN WORKORDER.parent
ELSE WORKORDER.wonum
END
          AND RELATEDRECORD.orgid=WORKORDER.orgid
AND RELATEDRECORD.siteid=WORKORDER.siteid
          AND RELATEDRECORD.relatedrecclass='WORKORDER'
ON SR.ticketid=RELATEDRECORD.recordkey
AND SR.orgid=RELATEDRECORD.orgid
AND SR.siteid=RELATEDRECORD.siteid
AND RELATEDRECORD.class='SR')
LEFT JOIN
frozen_quote@gqmfof
ON SR.ticketid = CUSTOMER_ENQUIRY_REF
AND SR.quotever = QUOTE_VERSION
Regards,
Arjun.

Answer 1

Check the plan of the non ansii version below against the plan of your version.
Sometimes they might be different as I remember hearing somewhere. The probability is not very high though as using ansii syntax some care
must be taken specifying predicates so the compared versions I heard about might well not be equivalent.
If the plans are the same and having indexes on linking columns in place I don't see what else could be done as accessing a remote database
can well be the major contribution the slow response you're experiencing.
select y.*,
       f.*
  from (select s.*,
               x.pscdate,x.ascdate,x.targstartdate,x.targcompdate,x.schedfinish,x.actfinish,x.estdur,x.wonum,x.mprn,
               x.sihousename wositehousename,x.sihouseno wositehouseno,x.sistreet wositestreet,
               x.sicounty wositecounty,x.siposttown wositeposttown,x.sipostcode wositepostcode,
               x.workorderid
          from (select r.recordkey,r.orgid,r.siteid,r.class,
                       w.pscdate,w.ascdate,w.targstartdate,w.targcompdate,w.schedfinish,w.actfinish,w.estdur,w.wonum,w.mprn,
                       w.sihousename wositehousename,w.sihouseno wositehouseno,w.sistreet wositestreet,
                       w.sicounty wositecounty,w.siposttown wositeposttown,w.sipostcode wositepostcode,
                       w.workorderid
                  from relatedrecord r,
                       workorder w
                 where r.relatedreckey = case when w.parent is null then w.wonum else w.parent end
                   and r.orgid = w.orgid
                   and r.siteid = w.siteid
                   and r.relatedrecclass = 'WORKORDER'
               ) x,
               sr s
         where x.recordkey = s.ticketid
           and x.orgid = s.orgid
           and x.siteid = s.siteid
           and x.class = 'SR'
       ) y,
       frozen_quote@gqmfof f
where y.ticketid = f.customer_enquiry_ref
   and y.quotever = f.quote_versionRegards
Etbin