How to debug slow queries in Django+Postgres
- by lacker
My database queries from Django are starting to take 1-2 seconds and I'm having trouble figuring out why. Not too big a site, about 1-2 requests per second (that hit Django; static files are just served from nginx.)
The thing that confuses me is, I can replicate the slowness in the Django shell using debug mode. But when I issue the exact same queries at an sql prompt they are fast. It takes about a second for a query to return, but when I check connection.queries it reports the time as under 10 ms.
Here's an example (from the Django shell):
>>> p = PlayerData.objects.get(uid="100000521952372")
>>> a = time.time(); p.save(); print time.time() - a
1.96812295914
>>> for d in connection.queries: print d["time"]
...
0.002
0.000
0.000
How can I figure out where this extra time is being spent?
I'm using Apache+mod_wsgi in daemon mode, but this happens with just the django shell as well, so I figure it is not apache-related.
