The list of functions that are delegated to a source depends on the datasource itself. Virtual DataPort populates the possible analytical, scalar and aggregate functions depends on the database adapter selected.
You can check the list of functions that are delegated to a datasource by referring the ‘Source Configuration’ tab of the datasource. You can find three fields that contains list of functions:
* Delegate aggregate functions list
* Delegate scalar functions list
* Delegate analytic functions list
If you do not want any of the functions in the list to be delegated, then you may enable the corresponding checkbox and remove the function from the list.
Also you can create Delegable Custom Functions and add them to this list, so that they are also delegated to the source.
You may refer to the ‘[Creating custom functions that can be delegated to the database](https://community.denodo.com/docs/html/browse/6.0/vdp/developer/developing_extensions/developing_custom_functions/creating_custom_functions_with_annotations#developing-custom-functions-that-can-be-delegated-to-a-database)’ section of Virtual DataPort Developer Guide for assistance on creating such functions.
Hope this helps!