Note
This option is only available when running an Oracle data warehouse.
By default, a load fails if a source column that is to be loaded does not exist. This default action can be modified by using the Allow Missing Source Columns feature of a load table. When this feature is enabled the load process will check all source columns, and if any are found to be missing will replace those missing columns with a Null value (which can be changed, see below).
On the Source tab of a Load table's Properties there are two check boxes and a drop-down list that we will cover in this section. See the following example:
Fields | Description | ||||||||
---|---|---|---|---|---|---|---|---|---|
Override Source Column/Transformation |
Note This box must be unselected to enable Allow Missing Source Columns support. | ||||||||
Allow Missing Source Columns | When this is enabled, the load process will examine every column in the load table. Based on the source table/source column fields associated with each column, it will check to see if the column exists in the source database. If the column exists normal processing will occur. If the column does not exist then a Null will be substituted for the column, and the load will proceed. | ||||||||
Exit Status When Missing Columns | If columns are found to be missing as a result of a Non Mandatory check then a message is recorded in the Audit trail and against the task if running in the Scheduler. The drop-down list of the same name allows the choice of action in the event of a missing column or columns. The choices are:
This drop-down list is only available if the Non Mandatory Source Columns check-box is ticked. | ||||||||
Limitations of Missing Column check | The check for missing columns will only examine and check those columns that are recorded in the source table and source column fields of a load table's column Properties. Therefore if a source column is used in a transformation or join, but is not recorded in the two fields mentioned above it will not be checked. |