Testing Columns

Column tests are meant to check for null and unique values, and are always run after transformations. This cannot be changed unless using a user-defined node.

Example Column Test

1. Click on Testing → Column.

2. Select both Unique and Null.

   

3. Now click on Null next to C_NATIONKEY. This will check to ensure all entries for this column are populated (not null).

4. Run the node and it should succeed, as there's no null entries.

   

5. Now try also selecting Unique for the C_NATIONKEY column. This will check to ensure all entries for this column are unique.

6. Run the node and it will fail, as C_NATIONKEY has repeated entries. Notice that the data was still processed, as column tests will always continue on failure.