[Linaro-validation] Going beyond the Django ORM limitations with Postgres

Hey Lava devs,

I realise that right now might not be the best time in the development cycle to mention this, but I've just watched an interesting talk on really using postgres with Django:

http://www.youtube.com/watch?v=S-kbfpRpVsY

In particular, I think the (already postgres-specific) horrific code I wrote for matching tags on job dispatch could be replaced with simple tags arrays on Job and Device and a "<@" operator.

There are some other bits that could potentially be used (e.g. the JSON stuff, maybe hstore for test results) but this part jumped out at me!

Cheers, mwh