How to make Purging better in terms of performance

Question

Hi
I am trying to purge(delete) data from 4 tables on the basis of a flag in the lookup table.
Now, there are 3 million records to be deleted from each of the 4 tables .
My piece of code is like this
for i in(select ids from lookup_table where flag_val='N')
loop
delete from table_a where id=i.ids;
delete from table_b where id=i.ids;
delete from table_c where id=i.ids;
delete from table_d where id=i.ids;
if commit_interval=5000 then
commit;
commit_interval:=0;
end if;
commit_interval:=commit_interval +1;
end;
I am trying to commit for 5000 records.
its taking a lot of time
like 10-12 hrs .
Can anyone solve this issue its urgent .
regards
shubh

Answer 1

Now in your code you have written delete statements for all the four tables. Now convert it to four different procedures each handling only a single table.
something like this.........
for i in(select ids from lookup_table where flag_val='N')
loop
delete from table_a where id=i.ids;
if commit_interval=5000 then
commit;
commit_interval:=0;
end if;
commit_interval:=commit_interval +1;
end;
for i in(select ids from lookup_table where flag_val='N')
loop
delete from table_b where id=i.ids;
if commit_interval=5000 then
commit;
commit_interval:=0;
end if;
commit_interval:=commit_interval +1;
end;
Run these procedures simultaneously.... say thru different windows/terminals.
Since these procedures are running simultaneously, the server efficiency will improve. Also make sure that the server is not used by other users/ less number of users so that max. resources are available for your code.