Creating derivations for dimension columns in the DataStage® Slowly Changing Dimension stage
By creating derivations for the dimension columns, you specify how to update the dimension table, including the values to use for new records and when records are set to expire.
Every dimension column must have a derivation. Columns with a purpose code of Current Indicator or Expiration Date must also have an Expire derivation. The following requirements apply:
- Columns with a purpose code of Type 1 or Type 2 must be derived from a source column.
- Columns with a purpose code of Current Indicator or Expiration Date must be derived from a literal value.
- Columns with a purpose code of SK Chain must be derived by using either the PrevSKChain function or the NextSKChain function.
- On the Output tab, open the Columns section, then click Edit. The Edit columns page opens.
- Create column derivations by editing a row in the Derivation column and using the expression editor.