Nullability in Px

yuva010 · Post by **yuva010** » Wed May 21, 2008 10:29 am

Hi,

There are few fields having nullable in source.
In target I have those fields nullable too. Do I need to handel those fileds, if my source value is null, in Parallel Extender?

ArndW · Post by **ArndW** » Wed May 21, 2008 10:36 am

No need to handle them at all. The only issue is when you try to write a null to a non-nullable column.

yuva010 · Post by **yuva010** » Wed May 21, 2008 10:54 am

Thanks,
Then why there is big issue in 'Nullability' handling in my team, I need to get it clarify...

ArndW · Post by **ArndW** » Wed May 21, 2008 11:15 am

Hard to answer that question, as you haven't specified what the "issue" is. Much of the time problems are encountered in transformations, where you get warnings or error when trying functions on null values.

yuva010 · Post by **yuva010** » Wed May 21, 2008 11:44 am

Nope.. The second question wasn't for you...
I need to get it clarify from my team.. they are continuously asking me, how are we handling nullability in the project... and we are not handling in any way b'coz all target fileds, possible of getting null value, are nullable.
And from your answer i got clarified.. now let me ask them..

vmcburney · Post by **vmcburney** » Wed May 21, 2008 5:09 pm

Your big issue with nulls in parallel jobs is whether you are using them in a lookup or transformation logic. If you pass a nullable source field straight through to a nullable target then you wont have a problem. If you try to run any type of Transformer trim, IF statement, compare, parse etc on it then whenever it has a null value in it you could lose that row - it could get spat out of your job. If you have nullable fields and you want to do something to them in a transformer you need to have a NullToValue around them first before you do anything else.

Unless you have profiled your data source and check the source application business rules and determined that the field is nullable but will never be null.

ag_ram · Post by **ag_ram** » Thu May 22, 2008 10:53 pm

yuva010 wrote:Thanks,
Then why there is big issue in 'Nullability' handling in my team, I need to get it clarify...

Did you get any chance to get it clarified?

yuva010 · Post by **yuva010** » Fri May 23, 2008 10:12 am

Nope yet.. but I have discussed this topic with senior architects here as well.. and they are saying we don't need such handling if our target is allowing us Null population.
But surely I'll talk with the concerned team, just to verify.

DSguru2B · Post by **DSguru2B** » Fri May 23, 2008 2:03 pm

I think your team's concern is more of a 'business type' rather than technical. Get this piece clarified.
At some shops, they want insane error handling even though it does not make sense. But at the least, make sure you are capturing the records that are getting rejected by the database due to nullability, or for any reason for that matter.