* Added the dependency for the PostgreSQL-driver
* Added the new profile
* Configured Flyway to apply db-specific SQL
* Added a PostgreSQL-DB to the setup for Docker Compose as "postgres"
* Added a named volume for the data of the service "postgres"
* Selected the new profile "prod" for the service "jdbc"
     image: jdbc:latest
     ports:
       - 8080:8080
+    environment:
+      spring.profiles.active: prod
+
+  postgres:
+    image: postgres:13
+    ports:
+      - 5432:5432
+    environment:
+      POSTGRES_USER: outbox
+      POSTGRES_PASSWORD: outbox
+      POSTGRES_DB: outbox
+    volumes:
+      - pgdata:/var/lib/postgresql/data/
+
+volumes:
+  pgdata:
 
        <groupId>com.h2database</groupId>
        <artifactId>h2</artifactId>
      </dependency>
+     <dependency>
+       <groupId>org.postgresql</groupId>
+       <artifactId>postgresql</artifactId>
+     </dependency>
      <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
 
     web:
       exposure:
         include: "*"
+
+spring:
+  flyway:
+    locations: classpath:db/migration/h2
+
+---
+
+spring:
+  profiles: prod
+  datasource:
+    url: jdbc:postgresql://postgres:5432/outbox
+    username: outbox
+    password: outbox
+  flyway:
+    locations: classpath:db/migration/postgres
 
+++ /dev/null
-CREATE TABLE users (id BIGINT PRIMARY KEY AUTO_INCREMENT, username VARCHAR(255), created TIMESTAMP, logged_in BIT);
 
--- /dev/null
+CREATE TABLE users (id BIGINT PRIMARY KEY AUTO_INCREMENT, username VARCHAR(255), created TIMESTAMP, logged_in BIT);
 
--- /dev/null
+CREATE SEQUENCE users_id_seq;
+CREATE TABLE users (id BIGINT PRIMARY KEY NOT NULL DEFAULT NEXTVAL('users_id_seq'), username VARCHAR(255), created TIMESTAMP, logged_in BOOLEAN);
+ALTER SEQUENCE users_id_seq OWNED BY users.id;