Slow loading of tabular forms in Application Express

Under some circumstances, there is an issue (observed in Application Express 4.1.1.00.23) that page tabular forms take very long to load, up to several minutes. Even if there is a very small dataset in the underlying table.  When I encountered this issue, the report ran fine on Development en Test environments, but in the almost identical production environment the page took minutes to load.

When examining the debug, I found the following line of Apex generated code, taking up to 30 seconds:

begin 
   select /*+ cardinality(t 10) */ 
         disp
       , val 
         bulk collect 
   into wwv_flow_utilities.g_display
      , wwv_flow_utilities.g_value 
   from table(wwv_flow_utilities.get_temp_lov_data(4)) t 
   order by insert_order, disp; 
end;

The main culprit appears to be the wwv_flow_utilities.get_temp_lov_data. This function is called whenever you create an item of the type “Select List (Named LOV)”. The workaround I found is to change the type to “Select List (Query Based LOV)” or “Select List (Static LOV)”. After altering the report attribute type, the report is loading normally.

Downside is that it will make your code less maintainable. Hopefully the problem is fixed in Apex 4.2.