Sample application.properties file

application.properties

# Here, spring.jpa.hibernate.ddl-auto can be none, update, create, create-drop, refer to the Hibernate documentation for details
# https://spring.io/guides/gs/accessing-data-mysql/
spring.jpa.hibernate.ddl-auto=none

# Connection details
spring.datasource.url=jdbc:postgresql://localhost:5432/db_name
spring.datasource.username=username
spring.datasource.password=password

# Disable feature detection by this undocumented parameter. Check the org.hibernate.engine.jdbc.internal.JdbcServiceImpl.configure method for more details.
spring.jpa.properties.hibernate.temp.use_jdbc_metadata_defaults = false

# Because detection is disabled you have to set correct dialect by hand.
spring.jpa.database-platform=org.hibernate.dialect.PostgreSQL9Dialect

# Maxiumum number of DB connections allowed
spring.datasource.hikari.maximum-pool-size=1