The APEX engine delegates data ordering an end-user can perform to the BOSS REST endpoint for server-side execution.

In addition, as necessary when defining a region based on a BOSS REST Data Source, you can specify an External Order Bys clause. Its syntax is a comma-separated list of one or more case-sensitive attribute names, each suffixed by :asc for ascending order or :desc for descending order. For example, the following external order bys expression would sort ascending by department number and then descending by date hired:

departmentNumber:asc,dateHired:desc

Note that an attempt to order by a BOSS attribute that is not configured to be sortable will result in a runtime error from the REST API. If you need to sort on a non-sortable attribute, this can be done by using the APEX Local Post-Processing feature that all REST Data Sources have available to use.