sorted input in aggregator

[cognos11]

i have three group by ports in aggregator transformation.
to improvie the performance, if i check 'sorted input' box, informatica assumes that to be already sorted by the group by ports.

In this scenario, how or where do i sort these values before reaching aggregator.Do i need to use a sorter transformation before that or should i use sql override in sql transformation where i explicitly mention order by in the sql as below.
eg select acct_id,amt,name,type from emp order by acct_id,amt,name,type.

What is the purpose of 'Number of Sorted Ports' option in source qualifier.

 

[Casemore]

I'm using Informatica v.5.1.1 so I'd do it using the 'Number of Sorted Ports' option that you mention in the source qualifier. This basically states the number of ports, beginning from port 1, in your source qualifier that should be sorted. So if you have:

Col1
Col2
Col3
Col4
Col5

and you want Col2, Col4, and Col5 sorted you'd input '3' into 'Number of sorted ports' and move the ports around so that you have:

Col2
Col4
Col5
Col1
Col3

I'm not sure, but I *think* that you should also run these into the first 3 ports in your next transformation. Actually, I don't think that's correct but bear it in mind. Of course though, you need to drag these from the sq for them to be picked up in the session sql.

If you're using v6 onwards then you might be better off with this Sort transformation you mention though.

Regards

Jon