Mappings code generation : regular SQL / cursor PL/SQL

Question

Hi,
When designing mappings, I fear that code generation can be potentially dangerous, because OWB automatically chooses the best method to generate the code (regular SQL or PL/SQL).
I am looking for some examples where code generation for a mapping:
- gives a regular SQL statement
- gives a cursor-based PL/SQL
- a small change in a mapping makes a regular SQL mapping to be transformed in a cursor-based PL/SQL
Thank you
Alexandre
Message was edited by:
Alexandre Abric

Answer 1

I have not said that different modes executes at the same way – what the use to have different options if they actually mean the same, right? I have said that they produced the same result i.e. if you expect the mapping to insert 1000 rows from the source to the target – it will be done no matter which operation mode you choose.
But by different ways. To keep it simple lets say that:
set base mode will result in:
insert into target (…)
select … from source;
row based will result in:
begin
for a in (select * from source) loop
insert … into target
end loop;
end;
Now lets assume that 5 rows from those 1000 you are going to insert, will break some NOT NULL constraint at the target.
If you choose Set-base mode entire insert from select will fail resulting no rows is inserted into target. Audit trail will contain message like “constraint … violated” and that’s it. You will have to find bad records by yourself.
If you choose Row-base mode – 995 rows will be inserted (depending on mapping configuration) into the target and 5 will be listed in audit trail with the same “ constraint violated” message.
That’s why default operating mode is “Set based fail over to Row based”. That means OWB will try to execute mapping in the fastest way – set based, but if it fail, it will try again to accomplish the task by running in row base mode, providing complete audit trail fro bad rows.