Sunday 1 January 2012

Why does not FastLoad allow duplicate rows?

The Reason behind Fastload not allowing Duplicate rows is the Restart Logic.
If  Fastload fails due to some reason and we restart the utility then it starts sending rows from the last checkpoint.
FastLoad doesn't have/store any information about the input record sequence like MultiLoad's Match Tag (ApplySeq+DMLSeq+ImportSeq+SMTSeq+SourceSeq).
So when its restarted simply doesn't know, if a row was duplicate within the data or was sent twice because of a restarted FastLoad (in Application Phase).


If FastLoad would be able to load MultiSet like MLoad, there would be more overhead regarding perm space.


Anoher line of thought is that FastLoad is older than MultiSet tables and there's no reason to add that feature as long as there's Mload.

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