django, render to response taking a lot of time

Question

I am using django to build an app that is slightly heavy on functionality. Consequently my templates are a bit heavy (nested loops, if conditions etc). I am noticing that 70% to 80% of time is spent in render_to_response step of my views. I haven't found anything indicating performance issues around template engine in django on google. Anyone here faced similar issues / any suggestions to solve this problem?

Answer 1

One thing to keep in mind is that QuerySet objects are lazy. They won't actually hit the database until you a perform an operation that requires the query to be executed (looping, counting, etc).

If you pass a QuerySet object in your template context, often a loop (or some other operation) inside your template will be what triggers the database call. When this happens, the template rendering is "penalized" for the database I/O, but the overall response time should be unaffected by whether it happens in the view or in the template rendering.