Overview: System Control Fields
Discovery Hub adds four additional fields on every table created. These, "system control fields" store helpful information about the records in each table.
- DW_Id: Stores an incremental integer uniquely identifying each row in a table which can be used as a surrogate key when needed.
- DW_Batch: Stores the batch or "execution number" within the table, linking each row with a specific execution.
- DW_SourceCode: Stores the name of the data source in which the row was originally generated from.
- DW_TimeStamp: Stores the date and time in which the row was populated.
While they will always be automatically generated on every table, system control fields can be shown or hidden in the Discovery Hub UI.
To do this, right click on a table, under advanced, click Show/Hide System Control Fields.
You can do this at the project level, but know it will only apply this setting on tables created in the project after enabling this setting. Right click on the project node, Edit Project, Advanced Settings, check Show System Control Fields.