Prevent loading every single element in the admin

arkindex/documents/admin.py

@@ -26,6 +26,7 @@ class ElementTypeInline(admin.TabularInline):
 
 class CorpusAdmin(admin.ModelAdmin):
     list_display = ('id', 'name', 'public', 'repository', 'top_level_type')
+    raw_id_fields = ('thumbnail', )
     search_fields = ('name', )
     inlines = (ElementTypeInline, UserMembershipInline, GroupMembershipInline)