We have a table (with columnSelection="multiple" and wrapped in a panel collection), where only some columns should be sortable. Setting sortable="false" on the those columns nicely removes the up/down arrow controls. Making the column unsortable - from that perspective. If we however access the the context menu (right click the column header) and navigate to "sort" Ascending and Descending is available, which thus still allows the user invoking sort on that column.
1. Download the test case and run the Application.
2. On the Main page right-click the Last Name column.
3. From the context menu select Sort and the Ascending or Descending
4. That triggers a sort of the column.
That the column could not be sorted, since its sortable attribute set to false.