# Handling null updates

The default handling of null updates is set in the [Advanced tab of the Settings - <ETL_Set_Name> window](https://help.qlik.com/en-US/compose/December2024/Content/ComposeDWDL/Main/DW/Data%20Warehouse/modify_etl_settings.htm). For each mapping, you can override the specified default.

To do this:

1. In the Manage Data Warehouse Tasks window, select the desired mapping.

2. Click the Null Updates toolbar button.

3. Select one of the available options. For a description of the options, see [Handling Null Updates](https://help.qlik.com/en-US/compose/December2024/Content/ComposeDWDL/Main/DW/Data%20Warehouse/modify_etl_settings.htm#null_values).