Aggregator after Sorter Transformation

[skumbhan]

Hello Members:

I am new to this forum and this is my first post. Please help me with it.

I am using a Sorter transformation before Aggregator transformation. I am sorting the data on column1 and using same column1 in Aggregator to define a group by clause.

Here the mapping works fine if i click the "Use Sorted input" option in the Aggregator. However if this option unchecked then the session fails to initialize.

Can some one throw some light on it.

Hope i made myself clear.

Thanks in advance.

Samit

 

[blom0344]

If you sort data in the correct way before an aggregator , then you SHOULD use the 'Use sorted input' option to have any benefit. However, performance gain is to be expected with partitioning.

AFAIK unchecking should not be the cause of the session not initializing. It will however cause the session to read all data first before starting aggregation, which can take a long, long time ...

Ties Blom
Information analyst

 

[skumbhan]

Hi bloom:

Thanks for your reply. Even i understand what you are saying. But the session is failing thats the reason. If you get time can you just try the scenario that i had asked for and let me know if it works.

Also if Sorter input comes from Source Qualifier then the Aggregator performs properly irrespective of SOrted input option checked or unchecked.

Thanks

Samit

 

[blom0344]

Samit,

The name is Blom, if you please

I just tested your case. In both cases there was no problem.
Looks like your session is not initializing because of another problem. Are you perhaps locking the output in any way?

Ties Blom
Information analyst