Upsert Statement
Posted: Sun Apr 21, 2013 9:37 pm
Hi All,
Requirement:A Delta extract will change to full extract at a specfic time period[Eg:say every 3 months].It will have the same version of the records in my datawarehouse only during that time period.
My approach:I am changing the write mode from insert to upsert in my oracle connector stage .Writing an update query that will only update the audit columns as to updating all the columns.
Any downside in this approach.If I update all the columns does it have any impact in terms of query performance. I know this is a database question but I am having a doubt with this approach as I have always filtered the unchanged records through ETL.This is the first time I using this approach due to time constraints.
Note:-The where clause columns are indexed.
Thanks in advance.
Regards,
Bala.
Requirement:A Delta extract will change to full extract at a specfic time period[Eg:say every 3 months].It will have the same version of the records in my datawarehouse only during that time period.
My approach:I am changing the write mode from insert to upsert in my oracle connector stage .Writing an update query that will only update the audit columns as to updating all the columns.
Any downside in this approach.If I update all the columns does it have any impact in terms of query performance. I know this is a database question but I am having a doubt with this approach as I have always filtered the unchanged records through ETL.This is the first time I using this approach due to time constraints.
Note:-The where clause columns are indexed.
Thanks in advance.
Regards,
Bala.