I have changed my Plone 4.3 setup to use
RelStorage[postgresql]. Now this doesn't perform as well as it could because the database server is not (yet) separated in a dedicated server; I suppose, the most important part would be the database to use its own disk (preferably an SSD). That's not my main question, but remarks are welcome.
My main question is: Can I use the most current PostgreSQL version, or should I e.g. stick with 9.x (for now)?
Because of Plone 4.3, I currently use RelStorage v1.6.3 (and psycopg2 v2.5.5).
I'd need to update PostgreSQL anyway because PostgreSQL 9.3 has reached its End Of Life in November 2018.
The only information about version considerations I could find so far is that "RelStorage 2.1 performs best with PostgreSQL 9.5 or above".
Of course I plan to update to Plone 5.2 and RelStorage 2.1+ during this year, but I'm not yet ready to do so.