Problem placing an extraction hint

Question

Hi,
I have a mapping that first uses a join between four tables, and then does nineteen lookups. This generates an SQL with an execution plan that is not optimal, and I need to place a hint at the top of the generated query. As far as I can tell Im not able to do that using OWB 9.2?
Consider a simple example using a join between two tables, and a single lookup. The generated sql is
select SOME_COLUMNS
from key_lookup_tab,
(select SOME_COLUMNS from table1) ingrp1,
(select SOME_COLUMNS from table2) ingrp2
where ingrp1.key = ingrp2.key
and ingrp1.another_key = key_lookup_tab.key (+)
What I want to do in this case is to insert a hint, eg
select /*+ NO_PUSH_PRED */ SOME_COLUMNS
from key_lookup_tab,
(select SOME_COLUMNS from table1) ingrp1,
(select SOME_COLUMNS from table2) ingrp2
where ingrp1.key = ingrp2.key
and ingrp1.another_key = key_lookup_tab.key (+)
How can I get this result? Configuring the mapping I can set extraction hints for table1 and table2, but that would only result in
select SOME_COLUMNS
from key_lookup_tab,
(select /*+ NO_PUSH_PRED */ SOME_VALUES from table1) ingrp1,
(select SOME_VALUES from table2) ingrp2
where ingrp1.key = ingrp2.key
and ingrp1.another_key = key_lookup_tab.key
Which does not work. And the Key_Lookup_tab does not allow the insertion of a hint in configure. Is there any way to get around this?
Regards,
Roald

Answer 1

Thanks for the quick response!
The workaround you suggest should work, but for the time being I think I'll just add the hint manually in the generated PLSQL code. (The mapping in question is only used for initial loading, and is fairly static)
Nice to see that this is getting fixed. We already have a few mappings containing joins with 20+ ingroups (from previous releases of OWB when key lookups were not available), and I don't think they are very easy to maintain. Large join conditions leave to much room for errors, which can be hard to spot.
Regards,
Roald