How filtering is done by Datastage Engine.

[bala_135]

Hi,

I am having a warning when I use reject rows in the constraint fields in the transformer.
CDC_version1_1..Sequential_File_30.DSLink29: 31357 Rows rejected.

When I try to the fill the constraint with the filter condition(say opposite of what I have mentioned in my previous constraint) I am not getting this warning.

I understand it is an intimation given at the log level.

What are the merits/de-merits in terms of filtering either way.
I am trying to understand how the datastage engine does this filter.


Thnaks in advance.
Regards,
Bala.

[chulett]

Not sure what you are asking. There's an entire section on reject handling and constraints in the help which would walk you through the various aspects of this.

Your warning that is being logged is an artifact of selecting the 'Reject Row' checkbox. The behaviour of what gets rejected can change if you add a constraint expression, but checking that box always gets you the reject row count logged as a warning if the count is non-zero.

[ray.wurlod]

Think of it as an alert, rather than as a warning. It also serves as a convenient mechanism to detect later that one or more rows rejected; without it you would need to determine the row count from that particular link. Design either way, depending on your particular style.