PushDown Optimization

PDO Overview:

http://dwbi.org/etl/informatica/162-pushdown-optimization-in-informatica

https://www.youtube.com/watch?v=zUouLglsJ4A
https://www.youtube.com/watch?v=qCqCwOYkCDk

PDO limitations:

1.     very much dependent on the database like, in case of full push down source and target should be in same database.

2.     Partitions you create in session for performance improvement may not work as thought since pushdown queries will overwrite those. 

3.     Some functions in exp transform returns unexpected output, add_to_date in teradata,Date_diff and ROUND not done properly. 

4.    When we configure session for full pushdown and all other criterions are matched, IS creates very complex queries to execute on database, this may in turn impact the performance. So blindly enabling pushdown may not improve performance always. 

5.     Transformation like rank and aggregate transformation cannot be pushed down. 

6.     In optimization viewer all the transformation which can be pushed down will be marked, looking at the queries generated and transformation which is excluded, we can redesign mapping wisely.

7.       When we implement PDO, the integration services send logic to databases. Because of this we cannot capture the rejected records in reject file.