[ii]

Python, of course.

#2. Python usually wins: http://www.alrond.com/en/2007/jan/25/performance-test-of-6-l...

#3. Django was written with Postgres in mind.

[ii]

And Python can be easily extended with C or even Assembly.

Here's the story of the guy who successfully optimized web app bottlenecks in C: http://fi.am/entry/the-limits-of-django-the-answers/