Document admin dead-end

events/admin.py

@@ -9,6 +9,21 @@ from .models import Event
 
 @admin.register(Event)
 class EventAdmin(admin.ModelAdmin):
+    # A note on performance: when using this particular (list) admin on the playground (~150K events), I ran into the
+    # fact that it was unusably slow (at least more slow than 30s to render). I examined this for a while, but in the
+    # end the conclusion was: "this will simply never work". There's simply too much brokenness here. The admin works
+    # fine for the "scaffolding" case, and perhaps for things like users, projects etc, but for the "main event"
+    # (events) we'll have to build it ourselves. Regarding the brokenness, some thoughts/links:
+    #
+    # * arbitrary sorting is (multiple columns) is possible, which means you'll need arbitrary indexes
+    # * https://code.djangoproject.com/ticket/8408
+    # * https://github.com/django/django/blob/9a3454f6046b/django/contrib/admin/options.py#L1816
+    #       no point of configuration for this one, I simply clobbered Django's code directly to turn it off
+    # * `actions_selection_counter = False` (possible to set as an admin option)
+    # * then I ran into the query itself just being super-slow (presumably caused by sorting)
+
+    # open question: when we'll "build this ourselves", is not some of the sqlite(?) slowness surfacing in other ways?
+
     ordering = ['-timestamp']
 
     search_fields = ['event_id', 'debug_info']