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Error in preserve partitioning when Joiner Stage Used

Posted: Fri Nov 12, 2004 5:54 am
by sushanth
Two Datasets are joining into a Target DB2 table with left outer Join
In all the stages, Iam making Sequential mode enabled then I receive all records which Iwant in the target
but with a warning like "When checking operator: Sequential operator cannot preserve partitioning of parallel dataset on input port 0 "

If I made all modes of all stages into Default Parallel, I will not receive warning but one record from right table will miss
pls do describe

Posted: Fri Nov 12, 2004 7:52 am
by T42
Do not worry about this warning message if this solution is producing the right data for you.

Normally, the Join Stage already handle the sort/partitioning for you, but in your observed case, it does not do the job. Maybe the datasets are sorted/partitioned earlier (and this noted behavior do propagate). You are overriding this behavior.

Do check earlier in the stream to see if you are doing sort/partitioning where you really don't have to. Otherwise, as long as you confirm with a large scale random test data (I'm talking about 1,000 rows per node), do not worry about this warning message.

Error in preserve partitioning when Joiner Stage Used

Posted: Tue Nov 16, 2004 1:54 am
by sushanth
Thanks, then we are not doing any sorting or Partitioing at the earlier stream means preceding stage (?) still we get this error.

Posted: Wed Nov 17, 2004 7:17 am
by T42
The framework actually insert in partitioning tasks where it is necessary/set by default. Read the online help for each stage, and use $APT_DUMP_SCORE to oserve this behavior. The information shared is a bit hard to read, though.