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PODjango query fast while rendering slow
 

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  1. PODjango query fast while rendering slow
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    <p>I'm running a website with Django and MySQL and I'm trying to optimize it. For that purpose I use the django debug toolbar and I pay a particular attention to the SQL part which is, I think, the reason why the load of my page is long.</p> <p>When I look at the SQL part in django debug toolbar, it says that my queries take around 90ms in total. But if I put a timer around the rendering function in python, then it takes more than 3s (which is closer to what I actually see when reloading the page)... </p> <p>How comes the query is that fast compared to the rendering?</p> <p>EDIT: here is the code in the template simplified to its maximum: </p> <pre><code>&lt;div id="content_annonces" class="ui-widget ui-corner-all"&gt; &lt;table&gt; {% if latest_annonces_list %} here goes the content {% else %} nothing found {% endif %} &lt;/table&gt; &lt;/div&gt; </code></pre> <p>as you can see, the only peace of code that is supposed to be costly is the SQL query requested when calling the object latest_annonces_list. But when I profile it with django debug toolbar it says this query has an elapsed of 90ms while the rendering takes around 3s ...</p> <p>And here goes the content of latest_annonces_list:</p> <pre><code>result = Annonce.objects.select_related('vehicule', 'vehicule__marque') .filter(vehicule__marque__in=self.marques).order_by('prix')[:10] </code></pre> <p>Models here:</p> <pre><code>class Marque(models.Model): name = models.CharField(db_index=True, primary_key=True, max_length=100) class Vehicule(models.Model): modele = models.CharField(primary_key=True, db_index=True, max_length=100) gen_modele = models.CharField(db_index=True, max_length=100) marque = models.ForeignKey(Marque) categories = models.ManyToManyField(Categorie) click = models.PositiveIntegerField(default=0) class Annonce(models.Model): vehicule = models.ForeignKey(Vehicule, db_index=True) porte = models.ForeignKey(Porte, db_index=True) carburant = models.ForeignKey(Carburant, db_index=True) bv = models.ForeignKey(Boite, db_index=True) prix = models.DecimalField(db_index=True,max_digits=8, decimal_places=2) km = models.PositiveIntegerField(db_index=True) dpt = models.CharField(db_index=True, max_length=50) annonceur = models.ForeignKey(Annonceur, db_index=True) img = models.URLField() url = models.URLField(max_length=2000) finition = models.CharField(max_length=500) cylindree = models.CharField(max_length=500) moteur = models.CharField(max_length=500) annee = models.DateTimeField(u'annee vehicule', db_index=True) pub_date = models.DateTimeField(u'date publication') last_touched = models.DateTimeField(u'derniere modification') last_scan = models.DateTimeField(u'dernier scan') type_ann = models.ForeignKey(Type_Annonce, db_index=True) type_vendeur = models.ForeignKey(Vendeu </code></pre> <p>r, db_index=True)</p>
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    1. USEagleOne
    1. USEagleOne
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    1. COCaptain Obvious here - maybe you have inefficient code in your rendering logic?
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      1. USRogach
    2. COwell I thought of it but the only thing that can be inefficient in the template is query related... The rest is just composed of strings basically...
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      1. USEagleOne
    3. COOk, I was just joking. The thing is that we can't say anything about the problem without seeing the code. Can you provide a small example of your problem?
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      1. USRogach
 

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