Null Value Handling

[Rajendran]

Hi,

Loading the data from transation table to Fact table, hash file is used for Lookup.

In transaction table one field having the Null value. This value i want to lookup with hash file.

How can i do?.

[vmcburney]

You've got dirty data. A null value where you were expecting a foreign key to another table.
Options:
- Fix the empty field in the source data with a data quality cleanup effort.
- default the value of the field within your ETL job so that it finds a value in the hash file.
- add a dummy row to your lookup table and when a null transaction value is found set the value to the dummy code.
- remove the referential integrity from your target database so the null value can be loaded into your fact table.

It's at this point that you go to your business analysts or end users with the option so they make the decision as to how to handle the problem.