Join stage same partition

debasisp · Post by **debasisp** » Tue May 05, 2009 12:27 am

Hi,
I am using a join stage .. There are two input links to the join stage and both of them are sorted and hash partition based upon a key COL1.. In the output I used same partition.. I want to know which input link partitioning information will be propagated to the output link(as it is same partition)...

ray.wurlod · Post by **ray.wurlod** » Tue May 05, 2009 12:29 am

Partitioning is only ever set on input links. Data on output links will always be the same as specified on the main input link. In your case, the Join stage has its inputs partitioned identically, so "main" does not come into consideration.

debasisp · Post by **debasisp** » Tue May 05, 2009 12:35 am

Thanks for your reply.

You are right. In the above example both the input links are having identical partitioning. If both the input links are not having same partitioning then in the join stage how will I know which one is "Main" link.

ray.wurlod · Post by **ray.wurlod** » Tue May 05, 2009 1:31 am

As I noted in my earlier post, "main" is not relevant in this case.

debasisp · Post by **debasisp** » Tue May 05, 2009 2:32 am

Hi,
Then in which case "Main" will come into consideration for Join stage?