Django query optimization

Question

I have a model with a lot of entries (more than 12,513,262) and they are supposed to increase exponentially. But the problem is due to this large no. entries querying is taking a lot of time is there a way to increase performance using indices etc.

My query is like this:

MyModel.objects.all().order_by('-timestamp')[0:50]

and its taking a lot of time to execute.

Answer 1

do you have an index on the timestamp field?

if you use south (for database migrations, you should definitely look into it if you aren't already), you can just add db_index=True to your field and migrate. Otherwise you can run

./manage.py sqlindexes MyApp

to show the sql statement adding the index. (which you need to run manually, e.g. using

./manage.py dbshell