difference btw filter and source qualifier??

[saifnawaz]

Hi guys,
Im an informatica newbee and have a question:
If the source qualifier transformation has a ' source filter ' option why would i want to use a filter transformation?

 

[ArtieChoke]

The source filter allows the database to do the filtering, so you will have less records to deal with in the entire workflow. It's better to have the db do the filtering if possible. Also note - you must write it in SQL (it's appended to the where clause) and is not evaluated until run-time.

Then there are times when you'll be doing lookups and filtering based on some condition that won't be known at the source, so you would use the filter transform.

"I think we're all Bozos on this bus!" - Firesign Theatre

 

[blom0344]

Source qualifier transformation will not be usefull if you want to filter data AFTER performing other transformations.
A common one is doing some lookups first, followed by aggregations and THEN wanting to apply a filter before writing to the target. I think about half of my mappings show such a structure........

T. Blom
Information analyst
tbl@shimano-eu.com