Null Handling for Change capture

[balajimadhav]

Hi,

I would like to know how the null columns has been handled while comparing in a change capture stage. I did a search on related topics which I couldn't get the information I was looking for and hence creating a new topic. I understand that from DataStage version 8.5 explicit handling eg: NullToValue() need not be handled. The scenario I have is two tables for which change capture to be made (Two columns in scope for change capture a nullable numeric and a nullable varchar field and a key field). When we don't do a explicit handle of null in transformer before the change capture on both links will it still the resultant output be a edit record or a copy record (for a record with values NULL in both columns)?

[chulett]

While I don't have the answer for you, that seems to me to be something you could very easily test for yourself. And then let us know the result.

[balajimadhav]

I tried that option as well now and i see when two null records (with null value of varchar and numeric fields) are compared against its corresponding before result using change capture , the result is a copy record (without any explicit null handling in transformer). I have come across few topics in forum that null should be handled to avoid an update/edit and hence raised this topic however not sure how a transformer handles the nullability in built

[prasson_ibm]

If the column type is nullable =Yes then datastage will put null so I don't think there is an issue in comparing two input links.

[kottinaresh]

Hi,

I have had the similar situation and as far as i know, nulls on both sides will be treated as same and won't see that as a edit record.

May be internally it will assign some value to null and compare that value #thought.

Thanks,
Naresh K