Configuring an Incremental Update for a Dimension

By default, all records of a dimension are updated at each refresh execution. However, for dimensions with large row counts, you may configure the dimension to update incrementally. Incremental updates are based on the DateTime field of the dimension. The initial population of the dimension only considers records from the data collection start time and then, at each refresh, from records corresponding to the update period. This limits the number of records to be processed at each refresh.

Alternatively, when you cannot use an incremental update, you may consider a dimension filter expression to limit the number of records handled at each refresh.

For example, if you configure a dimension with a refresh rate of 15 minutes and an update period of 1 hour every 15 minutes, the system will query the past hour of data and update the dimension table accordingly.

NOTE: When using the Historian data adapter, make sure that you configure the "Enable incremental update" on the Advanced tab with a "Data Collection Start" date / time.

To configure an incremental update for a dimension

1. Open the BI Gateway Model Builder.

2. Click the Add () icon in the Floating Action Buttons menu and then click the Dimension () button. A new dimension is added in the BI Gateway model with a default name and the Dimension editor appears in the right pane.

3. Click the Advanced tab.

4. Select the Incremental update check box. The Time reference field list shows the DateTime fields of the current dimension.

   

5. In the Data collection start list, click a data collection start date and time.

6. In the Time reference field list, click a dimension DateTime reference field for the update period.

   NOTE: This is the field on which the Data collection start time will be applied. The Time reference field list shows the DateTime fields of the current dimension.

7. In the Incremental Update Period area, do the following:

   1. In the Interval list, click the required update period for the dimension.

   2. In the Unit list, click the required unit of time for the update period. You can provide a minimum update period of one minute and a maximum update period of 366 days. The default update period is one day.

      Ensure that the update period is equal to or more than the refresh rate for the dimension.

8. Click Save.