i have a doubt as in my flat files are generated daily and it contains data from 1st of the month untill todate.
I am loading the data everyday into my oracle table... my question is whether it will load the duplicate rows or not ?? or will it skip and continue ?
If you just load data from file into table, you'll have duplicates. But don't panic there's allways solution for everithing, just try bit harder ;-)
1) if data in your file match values in table (previous days) I mean if you don't modify table data neither file data (previous days), just simply truncate table and populate it again.
2) if data are modified you can use WHEN clause in your control file and load today's data only
(use google for more details)
3) if there's nothing what helps you recognise today's data (some extract date or flag...) load all data into temporary table. compare both tables and load only those records which are missing in your table.
insert into TABLE
select * from tmp_TABLE tmp
where not exists (select 1 from TABLE t
where t.COL = tmp.COL
and t.COL2 = tmp.COL2