Update multiple fields using select query efficiently – 9i

Question

I need to populate a table called prop_charact used for synching data to a legacy system.
Prop_charact has fields that are found in a few other tables (no one field is found in more than one table outside of prop_charact). I want to pull the data from the corresponding fields in the source tables and put it into prop_charact. I only want to populate prop_charact with records that have been updated, but want to pull all fields for those records (whether or not that field has been updated). I am getting the list of updated records from a transaction history table.
After getting that list, I was not sure what to do with it.
I put what I want to do in terms of strictly SQL. I am thinking there are more efficient (less system resources) ways of doing this, but I am not sure what to pursue. I can use PL/SQL, but please keep in mind I am limited to using version 9i. Anyone have any hints about what I should look into using instead of just thes particular SQL statements?
insert into eval.prop_charact (parcelno, propertyid)
select distinct p.parcelno, p.propertyid
from eval.transaction_history tr,
admin.properties p
where tr.propertyid = p.propertyid
and trim(tr.tablename) in ('PROPERTIES', 'PROPERTYCHARACTERISTICS','EQID','NEWCHARACTERISTICS','DIMENSIONS', 'NON_RESIDENTIALS')
and trim(tr.fieldname) in ('BLDGCODE', 'CATCODE', 'UNFINISHED', 'TOPOGRAPHY', 'GARAGETYPE', 'GARAGESPACES', 'OPENSPACES',
'VIEW', 'GENERALCONSTRUCTION', 'YEARBUILT', 'ESTIMATEDYEAR', 'TOTALROOMS', 'TOTALBEDROOMS',
'BASEMENTTYPE', 'NUMBEROFFIREPLACES', 'HEAT', 'CENTRALAIR','CONDITION','SITE_TYPE','TOTALDWELLINGAREA',
'PLOTFRONT','PLOTDEPTH','PLOTSQFT','SHAPE','STORIES','FULLBATHROOMS','PARTBATHROOMS','MULTIPLE_BLDGS')
and tr.trans_date >= to_date('01-01-2010', 'MM/DD/YYYY')
and tr.trans_date < sysdate
order by p.parcelno;
update
select p.BLDGCODE pBLDGCODE, epc.BLDGCODE epcBLDGCODE, p.CATCODE pCATCODE,epc.CATCODE epcCATCODE,
p.UNFINISHED pUNFINISHED, epc.UNFINISHED epcUNFINISHED,
pc.TOPOGRAPHY pcTOPOGRAPHY, epc.TOPOGRAPHY epcTOPOGRAPHY,
pc.GARAGETYPE pcGARAGETYPE, epc.GARAGETYPE epcGARAGETYPE,
pc.GARAGESPACES pcGARAGESPACES, epc.GARAGESPACES epcGARAGESPACES,
pc.OPENSPACES pcOPENSPACES, epc.OPENSPACES epcOPENSPACES, pc.VIEW_ pcVIEW_, epc.VIEW_ epcVIEW_,
pc.GENERALCONSTRUCTION pcGENERALCONSTRUCTION,
epc.GENERALCONSTRUCTION epcGENERALCONSTRUCTION,
pc.YEARBUILT pcYEARBUILT, epc.YEARBUILT epcYEARBUILT,
pc.ESTIMATEDYEAR pcESTIMATEDYEAR, epc.ESTIMATEDYEAR epcESTIMATEDYEAR,
pc.TOTALROOMS pcTOTALROOMS, epc.TOTALROOMS epcTOTALROOMS,
pc.TOTALBEDROOMS pcTOTALBEDROOMS, epc.TOTALBEDROOMS epcTOTALBEDROOMS,
pc.BASEMENTTYPE pcBASEMENTTYPE, epc.BASEMENTTYPE epcBASEMENTTYPE,
pc.NUMBEROFFIREPLACES pcNUMBEROFFIREPLACES, epc.NUMBEROFFIREPLACES epcNUMBEROFFIREPLACES,
pc.HEAT pcHEAT, epc.HEAT epcHEAT, pc.CENTRALAIR pcCENTRALAIR, epc.CENTRALAIR epcCENTRALAIR,
e.CONDITION eCONDITION, epc.CONDITION epcCONDITION,
n.SITE_TYPE nSITE_TYPE, epc.SITE_TYPE epcSITE_TYPE,
d.TOTALDWELLINGAREA dTOTALDWELLINGAREA, epc.TOTALDWELLINGAREA epcTOTALDWELLINGAREA,
d.PLOTFRONT dPLOTFRONT, epc.PLOTFRONT epcPLOTFRONT,
d.PLOTDEPTH dPLOTDEPTH, epc.PLOTDEPTH epcPLOTDEPTH,
d.PLOTSQFT dPLOTSQFT, epc.PLOTSQFT epcPLOTSQFT,d.SHAPE dSHAPE, epc.SHAPE epcSHAPE,
pc.STORIES pcSTORIES, epc.STORIES epcSTORIES,
n.FULLBATHROOMS nFULLBATHROOMS,epc.FULLBATHROOMS epcFULLBATHROOMS,
n.PARTBATHROOMS nPARTBATHROOMS, epc.PARTBATHROOMS epcPARTBATHROOMS,
nr.MULTIPLE_BLDGS nrMULTIPLE_BLDGS, epc.MULTIPLE_BLDGS epcMULTIPLE_BLDGS
from eval.prop_charact epc, admin.properties p, admin.propertycharacteristics pc, admin.eqid e,
admin.dimensions d, eval.newcharacteristics n, EVAL.non_residentials nr
where epc.propertyid = p.propertyid and epc.propertyid = pc.propertyid and epc.propertyid = e.propertyid(+)
and epc.propertyid = d.propertyid(+) and epc.propertyid = n.propertyid(+) and epc.propertyid = nr.propertyid(+)
set epcBLDGCODE= pBLDGCODE, epcCATCODE= pCATCODE, epcUNFINISHED = pUNFINISHED,
epcTOPOGRAPHY = pcTOPOGRAPHY, epcGARAGETYPE = pcGARAGETYPE, epcGARAGESPACES = pcGARAGESPACES,
epcOPENSPACES = pcOPENSPACES, epcVIEW_ = pcVIEW_, epcGENERALCONSTRUCTION = pcGENERALCONSTRUCTION,
epcYEARBUILT = pcYEARBUILT, epcESTIMATEDYEAR = pcESTIMATEDYEAR, epcTOTALROOMS = pcTOTALROOMS,
epcTOTALBEDROOMS = pcTOTALBEDROOMS, epcBASEMENTTYPE = pcBASEMENTTYPE,
epcNUMBEROFFIREPLACES = pcNUMBEROFFIREPLACES, epcHEAT = pcHEAT, epcCENTRALAIR = pcCENTRALAIR,
epcCONDITION = eCONDITION, epcSITE_TYPE = nSITE_TYPE, epcTOTALDWELLINGAREA = dTOTALDWELLINGAREA,
epcPLOTFRONT = dPLOTFRONT, epcPLOTDEPTH = dPLOTDEPTH, epcPLOTSQFT = dPLOTSQFT,
epcSHAPE = dSHAPE, epcSTORIES = pcSTORIES, epcFULLBATHROOMS = nFULLBATHROOMS,
epcPARTBATHROOMS = nPARTBATHROOMS, epcMULTIPLE_BLDGS = nrMULTIPLE_BLDGS;

Answer 1

The following example may be of help.
SQL> create table mytable(col1 number(1),
  2  col2 date);
Table created.
SQL> insert into mytable values(1,sysdate);
1 row created.
SQL> select * from mytable;
      COL1 COL2
         1 20-AUG-04
SQL> update mytable
  2  set (col1,col2) = (select 2, sysdate-1 from dual);
1 row updated.
SQL> select * from mytable;
      COL1 COL2
         2 19-AUG-04