Hast Du Dir schon einmal die IBM Services (Object_Statistics) und IFS_OBJECT_STATISTICS angeschaut?

Beispiele:
Code:
Select ObjSize, x.*
  from Table(QSYS2.Object_Statistics(Object_Schema => '*ALLUSR', Objtypelist => '*ALL')) x
  Order By ObjSize Desc
  Limit 10;

Select Allocated_Size, Data_Size, x.*
  From Table(QSYS2.IFS_Object_Statistics(Start_Path_Name => '/home', Object_Type_List => '*ALLSTMF')) x
  Order By Data_Size Desc
  Limit 10;
;
... könnte allerdings ein bisschen dauern!