Hi Guys
It's been a while. :D
I have records going into a transformer and then split either of two ways, one to LN_BSNS and the other to LN_PERSONAL. More often than not, there are no records going down to LN_PERSONAL which in turn does a inner JOIN to a fairly large Dataset.
My question is this - should Dstage recognize that no records are present and avoid a potentially costly JOIN operation?
thanks
how clever is Dstage supposed to be?
Moderators: chulett, rschirm, roy
-
- Participant
- Posts: 54607
- Joined: Wed Oct 23, 2002 10:52 pm
- Location: Sydney, Australia
- Contact:
No.
The join won't be costly. It relies on the fact that its inputs are sorted not to be costly. "End of data" appearing on LN_PERSONAL will mean that the Join stage gets to close without doing anything.
The join won't be costly. It relies on the fact that its inputs are sorted not to be costly. "End of data" appearing on LN_PERSONAL will mean that the Join stage gets to close without doing anything.
IBM Software Services Group
Any contribution to this forum is my own opinion and does not necessarily reflect any position that IBM may hold.
Any contribution to this forum is my own opinion and does not necessarily reflect any position that IBM may hold.