如何删除django请求中的重复项

删除Django查询Image SQL duplicate中的重复项.我使用了SELECT_Related，并将请求数量从90个减少到18个，但是如果数据库增长，那么这并不能挽救我的生命.如何改进查询？

views.py

def index(request):  
    snj = ScheduleNotJob.objects.select_related()
    form = SNJ()
    return render(request,"index.html",{'snj': snj, 'form':form})  

models.py



class Office(models.Model):  
    title = models.CharField(max_length=150, db_index=True)  

    def __str__(self):
        return self.title
            

class Post(models.Model):
    office = models.ForeignKey(Office, on_delete=models.CASCADE)  
    title = models.CharField(max_length=150, db_index=True)

    def __str__(self):
        return self.title


class Human(models.Model):  
    office = models.ForeignKey(Office, on_delete=models.CASCADE)  
    post = ChainedForeignKey(
        Post, 
        chained_field="office",
        chained_model_field="office", 
        show_all=False, 
    )  
    initials = models.CharField(max_length=150, db_index=True)  


    def __str__(self):
        return self.initials


class Reason(models.Model):  
    title = models.CharField(max_length=150) 

    def __str__(self):
        return self.title


class Shift(models.Model):  
    title = models.CharField(max_length=150) 

    def __str__(self):
        return self.title
    

class ScheduleNotJob(models.Model):
    shift = models.ForeignKey(Shift, on_delete=models.CASCADE) 
    office = models.ForeignKey(Office, on_delete=models.CASCADE) 
    post = GroupedForeignKey(Post, "office") 
    human = GroupedForeignKey(Human, "post") 
    reason = models.ForeignKey(Reason, on_delete=models.CASCADE)
    comment = models.CharField(max_length=300, blank=True, null=True)
    length_time = models.IntegerField(blank=True, null=True)
    date_start = models.DateField(blank=True, null=True) 
    date_end = models.DateField(blank=True, null=True) 

index.html


{% for elem in snj %}  
    <tr class="mySelect">  
    <td>{{ elem.id }}</td>  
    <td>{{ elem.shift }}</td> 
    <td>{{ elem.office }}</td> 
    <td>{{ elem.post }}</td> 
    <td>{{ elem.human }}</td>  
    <td>{{ elem.reason }}</td>  
    <td>{{ elem.comment }}</td> 
{% endfor %}

我使用了SELECT_Related，并将请求数量从90个减少到18个，但是如果数据库增长，那么这并不能挽救我的生命.如何改进查询？