Subsequent Lookup Operators causes OWB to generate undeployable mappings

Question

Hi,
I am using OWB 11gR2 .
I am trying to create a fact loading mapping based on datavault.
That gives me error during deployment.
Validating and Generate doesn't give me an error.
So in trying to load the fact i tie various datavault tables together with a joiner operator.
All tables except the driving table are set to outer join role.
The output fields are tied to various lookup operator objects.
The output from those is tied to the target fact table.
All of this goes well, this mapping is deployable and upon genrate one can see the statements.
The problem arises when i try to insert another lookup operator between the output of one lookup operator and the fact.
That mapping does not give a validation error and also generate intermediate doesn't error.
Deploying doesn't work however, it complains of a incorrect identifier.
Inspecting the generate intermediate does reveal the problem:
OWB appends all of the join clauses from the first joiner to the total used for loading the fact as a where statement.
When you look at the first joiner though it just displays nicely all of the left outer join statements.
There is no where statement to be found on this first joiner.
It is only added at the fact stage at exactly the same place where the left outerjoins are from the first joiner.
Questions:
Is there a limit to the number of subsequent lookup operators one can use ? 2 can not be it i hope ..
Is there a patch for this ?
Other remarks; i have noticed that when i use more than 8 lookup operators on my canvas that the lookup conditons get corrupt.
It becomes something like: lookup.fieldname = null instead of lookup.fieldname = input.fieldname .
When this happens i have to correct every lookup operator on the mapping.
Is this known error ?
Hope somebody has an answer fro my first problem.
rgrds Mike
Edited by: MichaelR64 on 16-jan-2011 23:39

Answer 1

Hi,
I did some further testing:
This happens when there is an unequal number of lookups "attached"to the driving table.
What i mean is that if there is one lookup attached to a port of the driving table, then the next port that has a lookup can not have two (serially connected) lookups.
Or put the other way : if a port has two lookups(sequentially connected) than the errror disappears when all the other ports with lookups also have two lookups(serially connected that is).
At first i thought it had something to do with the joiner used in the first stage.
Replacing that with a view didn't solve it
In fact using a lookup where multiple rows output is specified causes owb to create this with a outer join.
It is this outer join part that is being mangled by owb as specified before.
If anyone can comment on this..