Commit after deleting records

Question

Hi All,
I wrote one delete command .This command deletes 20 millions of records.But I want to give "commit" after deleting every 100000 records. How to give "commit" for this requirement.
please guide me.
Thank you.

Answer 1

Depends on your delete statement.
Sometime you can group the delets into logical units.
Compare and consider the following three approaches.
1) This deletes all data from all previous months.Delete from myTable where insertDate < trunc(sysdate,'mm'))
2) Delete each month separately and commit in between.Delete from myTable where insertDate < trunc(sysdate,'year'));
commit;
Delete from myTable
where insertDate >= trunc(sysdate,'year'))
and insdate < add_months(trunc(sysdate,'year'),1) -- "january"
and insdate < trunc(sysdate,'mm')) -- do not delete too much!
commit;
Delete from myTable
where insertDate >= trunc(sysdate,'year'))
and insdate < add_months(trunc(sysdate,'year'),2) -- "February"
and insdate < trunc(sysdate,'mm')) -- do not delete too much!
commit;
Delete from myTable
where insertDate >= trunc(sysdate,'year'))
and insdate < add_months(trunc(sysdate,'year'),3) -- "March"
and insdate < trunc(sysdate,'mm')) -- do not delete too much!
commit;
Delete from myTable
where insertDate >= trunc(sysdate,'year'))
and insdate < add_months(trunc(sysdate,'year'),12) -- "December"
and insdate < trunc(sysdate,'mm')) -- do not delete too much!
commit;
3) Delete based on ID and logical groups
Select min(id), max(id) into v_min, v_max
from myTable where insertDate < trunc(sysdate,'mm'));
for i in 1..trunc(v_max-v_min)/100000)+1 loop
  delete from myTable
  where id >= v_min+((i-1)*100000)
  and id < v_min+(i*100000)
  and id <= v_max
  and insertDate < trunc(sysdate,'mm')) -- this line is not really needed, maybe remove it depending on the execution plan.
  commit;
end loop;