You might want to use a rule in different circumstances. You can add a rule to cleanse one or more data columns. You can add a lookup rule that provides information that the source data does not provide. You can add a rule to validate a cleansing rule for a data quality or data integration project.

When you create or edit a column profile, you can create a rule and add it to the profile, or apply an existing rule to the profile. You can use expression rules or predefined rules in a column profile.

After you run the profile, the Analyst tool displays the profile results for the rule column in summary view. You can view the column results for a rule in detailed view. The output of a rule can be one or more virtual columns. The virtual columns exist in the profile results. The Analyst tool runs a profile on the virtual columns. For example, you use a predefined rule that splits a column that contains first and last names into FIRST_NAME and LAST_NAME virtual columns. The Analyst tool runs the profile on the FIRST_NAME and LAST_NAME columns.