Webflux postgresql
There is no "official" reactive JDBC driver yet (as of March 2019). However, there are many 3rd party reactive drivers for postgres. I used David Moten's rxjava2-jdbc library and postgres jdbc driver
I wrote a tutorial/example using webflux, kotlin and postgres (rxjava2-jdbc) here:https://medium.com/@dvliman/building-a-reactive-web-service-with-spring-webflux-kotlin-and-postgresql-71c4e0c2f870
and the source code here: https://github.com/dvliman/spring-webflux-kotlin-postgresql/
but I wasn't using JPA - I would manually marshall data, write queries/functions to operate on the data.