I read the reference and understand the concept of trying to limit huge queries, but don't understand repr() or what's going on in this instance. My query already has a limit on it, but even if it was a bigger query, it is still intentional.
I have only one query set, and it is not iterated or accessed anywhere in the view. I have inserted debug logging statements to confirm there is only one SQL statement generated until the queryset is passed to the template - the count statement that Paginator needs to determine how many pages (omitted above because I knew why it was there). Then it generates 4 queries which doesn't seem right. I am doing some raw SQL in parallel with the query_set, maybe that is screwing it up? I am going to eliminate the querysets and try pure raw SQL for this view for performance reasons but I'd still like to understand what was going on. On Mar 12, 10:59 pm, Karen Tracey <kmtra...@gmail.com> wrote: > On Thu, Mar 12, 2009 at 11:24 PM, adrian <adrian...@gmail.com> wrote: > > > I have a view that does not evaluate a queryset, it just adds filters > > and order_by and then > > passes it to Paginator (set to 50 per page) and the result is passed > > to the template. The following SQL is generated (with some fields > > omitted for clarity). I'm using Django 1.0.2 and MySQL 5.1. > > > SELECT `lister_importedsighting`.`id`, > > `lister_importedsighting`.`user_id`, > > `lister_importedsighting`.`date_added`, > > `lister_importedsighting`.`active`, > > `lister_importedsighting`.`tax_order` FROM `lister_importedsighting` > > WHERE (`lister_importedsighting`.`user_id` = 1 AND > > `lister_importedsighting`.`birdlist_area` = ABA ) ORDER BY > > `lister_importedsighting`.`species_name` ASC LIMIT 50 > > > SELECT `lister_importedsighting`.`id`, > > `lister_importedsighting`.`user_id`, > > `lister_importedsighting`.`date_added`, > > `lister_importedsighting`.`active`, > > `lister_importedsighting`.`tax_order` FROM `lister_importedsighting` > > WHERE (`lister_importedsighting`.`user_id` = 1 AND > > `lister_importedsighting`.`birdlist_area` = ABA ) LIMIT 21 > > > SELECT `lister_importedsighting`.`id`, > > `lister_importedsighting`.`user_id`, > > `lister_importedsighting`.`date_added`, > > `lister_importedsighting`.`active`, > > `lister_importedsighting`.`tax_order` FROM `lister_importedsighting` > > WHERE (`lister_importedsighting`.`user_id` = 1 AND > > `lister_importedsighting`.`birdlist_area` = ABA ) ORDER BY > > `lister_importedsighting`.`species_name` ASC LIMIT 21 > > > SELECT `lister_importedsighting`.`id`, > > `lister_importedsighting`.`user_id`, > > `lister_importedsighting`.`date_added`, > > `lister_importedsighting`.`active`, > > `lister_importedsighting`.`tax_order` FROM `lister_importedsighting` > > WHERE (`lister_importedsighting`.`user_id` = 1 AND > > `lister_importedsighting`.`birdlist_area` = ABA ) ORDER BY > > `lister_importedsighting`.`species_name` ASC LIMIT 21 > > > My question is why are the last 3 queries present, and where did limit > > 21 come from, a number not present in my view at all? > > They're coming from some code attempting to print or take the repr of the > queryset. See: > > http://groups.google.com/group/django-users/msg/e20328499c793e41 > > (It looks like there may be more than one queryset variable involved here -- > one of those LIMIT 21 queries doesn't have an order by clause.) > > > It matters because in some cases my SQL queries are much more > > expensive than this, and they > > run for every page if Paginated. > > If it's not immediately clear to you where these calls to repr are coming > from it might be worth trying to track them down. Years ago querysets in a > template context would get evaluated as a side-effect of attempting to > access a non-existant template variable > (seehttp://groups.google.com/group/django-users/browse_thread/thread/82df...) > but that was fixed a long time ago. It looks like something, though, is > doing similar with the querysets you are working with here. Are you running > with any debugging plugins or other code that might be doing processing on > your template context? > > Karen --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Django users" group. To post to this group, send email to django-users@googlegroups.com To unsubscribe from this group, send email to django-users+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/django-users?hl=en -~----------~----~----~----~------~----~------~--~---
