giannisp

After automatically updating Postgres to 10.0 via Homebrew, the pg_ctl start command didn't work.
The error was "The data directory was initialized by PostgreSQL version 9.6, which is not compatible with this version 10.0."

Database files have to be updated before starting the server, here are the steps that had to be followed:

# need to have both 9.6.x and latest 10.0 installed, and keep 10.0 as default
brew unlink postgresql
brew install postgresql@9.6
brew unlink postgresql@9.6
brew link postgresql

inklesspen

(This gist is pretty old; I've written up my current approach to the Pyramid integration on this blog post, but that blog post doesn't go into the transactional management, so you may still find this useful.)

Fast and flexible unit tests with live Postgres databases and fixtures

I've created a Pyramid scaffold which integrates Alembic, a migration tool, with the standard SQLAlchemy scaffold. (It also configures the Mako template system, because I prefer Mako.)

I am also using PostgreSQL for my database. PostgreSQL supports nested transactions. This means I can setup the tables at the beginning of the test session, then start a transaction before each test happens and roll it back after the test; in turn, this means my tests operate in the same environment I expect to use in production, but they are also fast.

I based my approach on [sontek's blog post](http://sontek.net/blog/