Performance turning problem please help!!!!!!!!!!!!!!!!!!!!!

Question

I have the script below and the explain plan
select
leaseid detail_lease,
unit,
bldgid bldgid_A,
bldgname,
orgdesc1,
space_uom,
sum(area) Area
from (
SELECT DECODE (mc.MASTER,
NULL, sl.leaseid,
mc.MASTER
) AS leaseid,
DECODE (SUBSTR (sl.bldgid, 1, 1),
'P', 'PARK',
'SQMTR'
) AS unit,
sl.bldgid, f.flrname,
-- chg 19602 not to show Unassigned area
--NVL (o.orgdesc1, 'Unassigned') AS orgdesc1,
orgdesc1,
-- chg 19602
SUM (DECODE (SUBSTR (sl.bldgid, 1, 1),'P', 1,NVL (Cst_Convert_Uom (s.spuarea,s.uom_std_id,'METR_MTR') * so.PERCENT *.01,0)
) AS area,
DECODE (SUBSTR (sl.bldgid, 1, 1),
'P', 'PARK',
'SQMTR'
) AS space_uom,
NVL (bldg.bldgname, l.lgldesc) AS bldgname
FROM fisinterface.vfis_lease_master_component mc,
space_lease sl,
FLOOR f,
(SELECT spaceorg.bldgid, spaceorg.flrid, spaceorg.spid,
spaceorg.orgid,spaceorg.PERCENT
FROM spaceorg
WHERE TRUNC (SYSDATE) >=
NVL (TRUNC (spaceorg.start_date), TRUNC(SYSDATE) - 1)
AND TRUNC (SYSDATE) <=
NVL (TRUNC (spaceorg.end_date), TRUNC(SYSDATE) + 1)) so,
org o,
lease l,
SPACE s,
vfis_bldg_main_name bldg
WHERE sl.leaseid = mc.component(+)
AND f.bldgid = s.bldgid ||''
AND f.flrid = s.flrid ||''
AND s.bldgid = so.bldgid(+)
AND s.flrid = so.flrid(+)
AND s.spid = so.spid(+)
AND so.orgid = o.orgid(+)
AND s.bldgid = sl.bldgid
AND s.flrid = sl.flrid
AND SUBSTR(S.SPSTATOW,1,1) = 'A'
AND s.spid = sl.spid
AND DECODE (mc.MASTER, NULL, sl.leaseid, mc.MASTER) =
l.leaseid
AND l.ltflag = 'T'
AND s.bldgid = bldg.bldgid(+)
GROUP BY DECODE (mc.MASTER, NULL, sl.leaseid, mc.MASTER),
DECODE (SUBSTR (sl.bldgid, 1, 1), 'P', 'PARK', 'SQMTR'),
sl.bldgid,
f.flrname,
o.orgdesc1,
DECODE (SUBSTR (sl.bldgid, 1, 1), 'P', 'PARK', 'SQMTR'),
NVL (bldg.bldgname, l.lgldesc))
GROUP BY leaseid, unit,bldgid , bldgname, orgdesc1,space_uom
ORDER BY LEASEID ,bldgid, ORGDESC1
EXPLAIN PLAN
Operation     Object Name     Rows     Bytes     Cost     Object Node     In/Out     PStart     PStop
SELECT STATEMENT Optimizer Mode=ALL_ROWS          87           1562                     
SORT GROUP BY          87      91 K     1562                     
VIEW          87      91 K     1561                     
HASH GROUP BY          87      23 K     1561                     
HASH JOIN          87      23 K     1560                     
HASH JOIN          87      21 K     1518                     
TABLE ACCESS BY INDEX ROWID     FAMIS.LEASE     1 K     79 K     62                     
INDEX RANGE SCAN     FAMIS.LEASE_LTFLAG_I     1 K          2                     
HASH JOIN OUTER          837      153 K     1456                     
HASH JOIN OUTER          406      63 K     1163                     
HASH JOIN OUTER          406      55 K     841                     
NESTED LOOPS OUTER          406      41 K     834                     
HASH JOIN          406      25 K     529                     
TABLE ACCESS FULL     FAMIS.SPACE     1 K     41 K     467                     
INDEX FAST FULL SCAN     FAMIS.SPACE_LEASE_PK     40 K     1 M     61                     
TABLE ACCESS BY INDEX ROWID     FAMIS.SPACEORG     1      40      1                     
INDEX RANGE SCAN     FAMIS.CST_SPACEORG_BFSPID     1           1                     
TABLE ACCESS FULL     FAMIS.ORG     1 K     46 K     7                     
VIEW     FISINTERFACE.VFIS_LEASE_MASTER_COMPONENT     2 K     39 K     322                     
HASH UNIQUE          2 K     588 K     322                     
HASH JOIN          2 K     588 K     188                     
HASH JOIN          2 K     333 K     112                     
TABLE ACCESS FULL     FAMIS.LEASE     7 K     965 K     76                     
TABLE ACCESS BY INDEX ROWID     FAMIS.BUILDING_JOURNAL     12 K     322 K     292                     
INDEX RANGE SCAN     FAMIS.CST_BUILDING_JOURNAL_TYPE_IX     12 K          37                     
TABLE ACCESS FULL     FAMIS.FLOOR     11 K     285 K     41                     
The space table has 118488 records and its doing a full table scan. the primary key in this table is BLDGID, FLRID, SPID
vfis_lease_master_component is a view and has 7737 records and a full scan is done.
re_doc_relationship is a view with 10833 and doing a full table scan
lease is a table with 13807 records and a full table can is performed the primary key is lease ID
Floor is a table with 1125 records and it doing a full table scan The primary key is
Bldgid, flrid.
Am using this query in oracle reports and the report is timming out in the browser which is not acceptable to the user. Any help will be greately appreciated.
Thank you.

Answer 1

When I first saw this, I thought I would skip my evening SuDoKu and do this SQL instead. Well, in the end I did the SuDoKu and managed only to make the SQL readable.
select leaseid detail_lease
      ,unit
      ,bldgid bldgid_A
      ,bldgname
      ,orgdesc1
      ,space_uom
      ,sum(area) Area
from  (SELECT DECODE (mc.MASTER
                     ,NULL, sl.leaseid
                     ,mc.MASTER) AS leaseid
             ,DECODE (SUBSTR (sl.bldgid, 1, 1)
                     ,'P', 'PARK'
                     ,'SQMTR') AS unit
             ,sl.bldgid
             ,f.flrname
             ,orgdesc1
             ,SUM (DECODE (SUBSTR (sl.bldgid, 1, 1)
                          ,'P', 1
                          ,NVL (Cst_Convert_Uom (s.spuarea,s.uom_std_id,'METR_MTR') * so.PERCENT *.01,0))) AS area
             ,DECODE (SUBSTR (sl.bldgid, 1, 1)
                     ,'P', 'PARK'
                     ,'SQMTR') AS space_uom
             ,NVL (bldg.bldgname, l.lgldesc) AS bldgname
       FROM   fisinterface.vfis_lease_master_component mc
             ,space_lease sl
             ,FLOOR f
             ,(SELECT spaceorg.bldgid
                     ,spaceorg.flrid
                     ,spaceorg.spid
                     ,spaceorg.orgid
                     ,spaceorg.PERCENT
               FROM   spaceorg
               WHERE  TRUNC (SYSDATE) >= NVL (TRUNC (spaceorg.start_date), TRUNC(SYSDATE) - 1)
                 AND  TRUNC (SYSDATE) <= NVL (TRUNC (spaceorg.end_date), TRUNC(SYSDATE) + 1)) so
             ,org o
             ,lease l
             ,SPACE s
             ,vfis_bldg_main_name bldg
       WHERE  sl.leaseid = mc.component(+)
         AND  f.bldgid   = s.bldgid ||''
         AND  f.flrid    = s.flrid ||''
         AND  s.bldgid   = so.bldgid(+)
         AND  s.flrid    = so.flrid(+)
         AND  s.spid     = so.spid(+)
         AND  so.orgid   = o.orgid(+)
         AND  s.bldgid   = sl.bldgid
         AND  s.flrid    = sl.flrid
         AND  s.spid     = sl.spid
         AND  l.ltflag   = 'T'
         AND  s.bldgid   = bldg.bldgid(+)
         AND  SUBSTR(S.SPSTATOW,1,1) = 'A'
         AND  DECODE (mc.MASTER
                     ,NULL, sl.leaseid
                     ,mc.MASTER) = l.leaseid
       GROUP  BY DECODE (mc.MASTER
                        ,NULL, sl.leaseid
                        ,mc.MASTER)
                ,DECODE (SUBSTR (sl.bldgid, 1, 1)
                        ,'P', 'PARK'
                        ,'SQMTR')
                ,sl.bldgid
                ,f.flrname
                ,o.orgdesc1
                ,DECODE (SUBSTR (sl.bldgid, 1, 1)
                        ,'P', 'PARK'
                        ,'SQMTR')
                ,NVL (bldg.bldgname, l.lgldesc))
GROUP  BY leaseid
         ,unit
         ,bldgid
         ,bldgname
         ,orgdesc1
         ,space_uom
ORDER BY  LEASEID
         ,bldgid
         ,ORGDESC1At first, we have a select with a few columns, group by and order by. No problem... Except, what about the "from"?
This is itself a select with a group by.... Also nothing special.
Only, the inner select is picking data from eight tables, of which one is itself a select, then adding four outer joints.
I think this is where the combination of parser and optimizer is about to give up. No amount of tuning will really solve that problem.
I believe the creators of the database state that one should not join more than five tables in a select.
Maybe a couple of views on some of the data would help?
In my opinion, there has got to be a design issue stuck here somewhere and modifying the select isn't really going to solve that.
Sorry.... My opinion.... Maybe someone else has better advice....