The Integration Service generates a begin date for each new and changed dimension it inserts into the target, using the current system date. The end date for these dimensions is NULL.
Each time the Integration Service inserts a changed dimension, it updates the previous version of the dimension in the target, using the current system date to fill the previously null end date column.
As a result, all current dimension data in the Type 2 Dimension/Effective Date Range target have null values in the PM_END_DATE column. All previous versions of dimension data have a system date in PM_END_DATE to indicate the end of the effective date range for each version.
For example, the following dimensions are current dimension data since their end date columns are null:
When the Integration Service finds updated versions of these dimensions in the source, it inserts them into the target, using the system date to indicate the beginning of their effective date ranges and leaving the end dates null.
The Integration Service also updates the existing versions in the target, entering the system date to end the effective date range: