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Blocking

Posted: Thu Jun 18, 2009 2:03 am
by dalecooper
Hi

Another Matching question:

Looks like it is not a good idea to block on null columns?
Example:
MatchColumn1 MatchColumn2
CompName B
CompName
CompName C

The above result will be that no blocking is done.
The only way to get it matched is using the following:
Block on MatchColumn1 and do the matching
on MatchColumn2, Critical missing ok.

Is that correct?
Shouldn't it be possible to block on null values?

Regards
Dale

Posted: Thu Jun 18, 2009 6:48 am
by JRodriguez
Dale,

All records containing nulls values in columns that are part of your blocking criteria become residuals, but will be available for next passes where you can have a different blocking criteria using other columns

It is always possible to handle nulls values in any previous step (standardization ?) and default a value for any nulls...

Posted: Thu Jun 18, 2009 7:16 am
by dalecooper
Thanks again Julio!

Posted: Thu Jun 18, 2009 8:02 am
by JRodriguez
Dale,

All records containing nulls values in columns that are part of your blocking criteria become residuals, but will be available for next passes where you can have a different blocking criteria using other columns

It is always possible to handle nulls values in any previous step (standardization ?) and default a value for any nulls...