This error is mostly harmless but is creating a lot of confusion to users upgrading to Spring Boot 2.0 which has gone GA, suddenly seeing exceptions in the log which weren't there before.

https://github.com/spring-projects/spring-boot/issues/12007
https://stackoverflow.com/questions/46493500/hibernate-with-c3p0-createclob-is-not-yet-implemented
https://stackoverflow.com/questions/49110818/method-org-postgresql-jdbc-pgconnection-createclob-is-not-yet-implemented