PostgreSQL 9.1 Deprecation
Change effective on 22 February 2016
Heroku is deprecating support for all databases running PostgreSQL 9.1. This deprecation is part of our documented version support policy.
Deprecated Postgres databases will be automatically migrated to the latest version of Postgres on or after June 1, 2016. We urge customers to migrate and update their databases themselves prior to this date so that they can test application computability and perform the migration on their own schedule.