Add Support for Postgres

[aneiderhiser]

From a Tuva user:

• We ideally want to run tuva on top of postgres. This is primarily to combine w/ our transactional db (and where our other reporting data lives) and a little for cost optimization.
• I got through most of the hurdles here, but got stumped with the nulls in the other_provider reference files. The rds postgres / s3 loader doesn't support custom null operators. I plan to make my own copy of the reference files and import manually when I get more time.
• Some of the queries for the quality measure data marts aren't compatible with postgres - this data mart isn't critical for us, so nbd.

[cesararevalo]

@aneiderhiser hey did you get this working? I was looking to try the Tuva platform also on top of postgresql, and it would be nice if this was supported already. Anyways, let me know, thanks in advance! -C

[aneiderhiser]

@cesararevalo sorry not yet :-(

[shariharan99]

I would support this enhancement!