title: How to add custom setting in postgres in Heroku?
body: <p>I have a Spring Boot application which runs as API service for a mobile app, the back-end application uses PostgreSQL database and encrypts some columns for customer user data such as payment info, password, etc...
  Now the encryption in Spring Boot is done via <code>@ColumnTransformer</code> with <code>read</code> and <code>write</code> annotation params I am using PgCrypto to encrypt by importing key by doing PostgreSQL query
  <code>current_setting('encrypt.key')</code>. Now the issue is that I haven't found a way to add a custom settings such as <code>encrypt.key</code> PostgreSQL settings in Heroku, can anyone please tell me a solution for this problem?</p>