Improving performance of an Django MPTT tree

Question

I have implemented the follow model to capture the structure of a classical piece of music. I'm using the MPTT to implement movements, opera acts and arias.

model.py:

TreeForeignKey(Work, blank=True, null=True, db_index=True, on_delete=models.PROTECT).contribute_to_class(Work, 'parent')
mptt.register(Work, order_insertion_by=['id'])

class Work(models.Model):
    attributed_to = models.NullBooleanField()
    name = models.CharField(max_length=400, null=True, blank=True)
    lang = models.CharField(max_length=2, null=True, blank=True)
    name_original = models.CharField(max_length=200, null=True, blank=True)
    lang_original = models.CharField(max_length=2, null=True, blank=True)
    name_common = models.CharField(max_length=200, null=True, blank=True)
    name_common_orig = models.CharField(max_length=200, null=True, blank=True)
    dedicated_to = models.CharField(max_length=200, null=True, blank=True)
    pic = models.ImageField(upload_to = 'pic_folder/', default = '/pic_folder/None/no-img.jpg')
    piece_type = models.CharField(max_length=100, null=True, blank=True)
    category = models.CharField(max_length=100, null=True, blank=True)
    date_start = models.CharField(max_length=100, null=True, blank=True)
    date_start_gran = models.CharField(max_length=5, choices=DATE_TYPES, default='Year')
    date_signature = models.CharField(max_length=100, null=True, blank=True)
    date_signature_gran = models.CharField(max_length=10, choices=DATE_TYPES, default='Year')
    around = models.BooleanField(null=True)
    date_published = models.CharField(max_length=100, null=True, blank=True)
    date_published_gran = models.CharField(max_length=10, choices=DATE_TYPES, default='Year')
    desc = models.TextField(max_length=8000, null=True, blank=True)
    order = models.CharField(max_length=100, null=True, blank=True)


class Work_Music(Work):
    composer = models.ForeignKey(Composer, verbose_name=_('composer'), null=True, blank=True, on_delete=models.PROTECT)
    key = models.CharField(max_length=10, null=True, blank=True)
    tonality = models.CharField(max_length=20, null=True, blank=True)

Here is the view.py:

class ComposerOverviewView(TemplateView):
    template_name = 'composers/overview/catalogue.html'

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)

        opus = Work_Music.objects.filter(composer=self.kwargs['pk'], level=0)

        context.update({
            'composer': Composer.objects.get(pk=self.kwargs['pk']),
            'opus': opus,
        })
        return context

When I try to run a query for all of the works for a composer (in the DB there are a total of 264 works), the queryset take almost 6 secs to run. I was wondering if anyone knows how to improve my code to increase the performance. There seems to be some with the delay_mptt_updates() method. But I'm not sure where it would go in my code.

I read in another article that MPTT sometimes does run slow. If I can increase the performance, what are some other alternatives?

Improving performance of an Django MPTT tree

0 Answers0