SQL Query Executing longer time

Question

Hi , The below SQL query executing longer time . Please help to Improve the query performance. The query continuously running for more than 24 hours and failing with roolback segment error. Not getting the final output. Most of the tables are having milions of records.
Select distinct
IBS.ADSL_ACCESS_INFO,
IBS.LIJ ,
regexp_substr(OBVS.REFERENTIE_A,'[[:digit:]]+') as O_NUMBER,
DBS.CKR_NUMMER_CONTRACTANT,
DBS.DNUMBER
FROM CD.IBS,
CD.OIBL,
CD.IH,
CD.ODL,
CD.OH,
CD.DBS,
CD.OBVS
Where IBS.END_DT = To_Date('31129999', 'ddmmyyyy')
AND OIBL.END_DT = to_date('31129999', 'ddmmyyyy')
AND DBS.END_DT = to_date('31129999', 'ddmmyyyy')
AND OBVS.END_DT = to_date('31129999', 'ddmmyyyy')
AND OBVS.REFERENTIE_A LIKE 'OFM%'
AND OIBL.INFRA_KEY = IH.INFRA_KEY
AND OIBL.ORDERS_KEY = OH.ORDERS_KEY
AND IBS.INFH_ID = IH.INFH_ID
AND ODL.ORDH_ID = OH.ORDH_ID
AND DBS.DEBH_ID = ODL.DEBH_ID
AND OBVS.ORDH_ID = ODL.ORDH_ID
Order By IBS.LIJ
All the columns which are present in the where condition are having either Index/key (Primary/unique) except END_DT column.
Please Advise

Answer 1

Predicate pushing can help when it greatlly restricts the number of rows - you must experiment - might not work with all predicates pushed (as shown here)
select distinct
       ibs.adsl_access_info,
       ibs.lij,
       obvs.o_number,
       dbs.ckr_nummer_contractant,
       dbs.dnumber
  from (select infh_id,adsl_access_info,lij
          from cd.ibs
         where end_dt = to_date('31129999','ddmmyyyy')
       ) ibs,
       (select infra_key,orders_key
          from cd.oibl
         where end_dt = to_date('31129999','ddmmyyyy')
       ) oibl,
       (select ordh_id,regexp_substr(obvs.referentie_a,'[[:digit:]]+') as o_number
          from cd.obvs
         where end_dt = to_date('31129999','ddmmyyyy')
           and referentie_a like 'OFM%'
       ) obvs,
       (select debh_id,ckr_nummer_contractant,dnumber
          from cd.dbs
         where end_dt = to_date('31129999','ddmmyyyy')
       ) dbs,
       cd.ih,
       cd.odl,
       cd.oh
where oibl.infra_key = ih.infra_key
   and oibl.orders_key = oh.orders_key
   and ibs.infh_id = ih.infh_id
   and odl.ordh_id = oh.ordh_id
   and dbs.debh_id = odl.debh_id
   and obvs.ordh_id = odl.ordh_id
order by ibs.lijRegards
Etbin