Normalized Tables Overview > Adding additional columns
  
Adding additional columns
With the columns of the normalized table displayed in the middle pane, this pane is considered a drop target for additional columns.
It is a simple matter to select columns from other load and/or stage tables and drag these columns into the middle pane. The source table column in the middle pane shows where each column was dragged from. The column description could be acquired from three different tables. The best practice is to rename at least two of the columns, perhaps also adding context to the column name. For example, description could become group_description, and so forth.
There are a number of QAD Data Warehouse Designer ancillary columns that do not have a source table. These columns have been added by QAD Data Warehouse Designer, and are added depending on earlier choices. A description of these columns follows.
Column name
Description
dss_start_date
Used for history tables. This column provides a date time stamp when the normalized table record came into existence. It is used to ascertain which normalized table record should be used when multiple are available.
dss_end_date
Used for history tables. This column provides a date time stamp when the normalized table record ceased to be the current record. It is used to ascertain which normalized table record should be used when multiple are available.
dss_current_flag
Used for normalized history tables. This flag identifies the current record where multiple versions exist.
dss_source_system_key
Added to support history tables that cannot be fully conformed, and the inclusion of subsequent source systems. See the ancillary settings section for more details.
dss_version
Used for normalized history tables. This column contains the version number of a normalized history tables record. Numbered from 1 upwards with the highest number being the latest or current version. It forms part of the unique constraint for the business key of a normalized history tables.
dss_update_time
Indicates when the record was last updated in the data warehouse.
dss_create_time
Indicates when the record was first created in the data warehouse