title: How do I configure PostgreSQL with Grails 3.0?
body: <p>I am using IntelliJ IDEA 15.0.2 as an IDE. I have created a Grails 3.0 application and changed it a bit to configure PostgreSQL.</p>
  
  <p>Here is my dataSource:</p>
  
  <pre><code>dataSource:
  pooled: true
  jmxExport: true
  driverClassName: org.postgresql.Driver
  username: postgres
  password: root
  
  environments:
  development:
      dataSource:
          dbCreate: update
          url: jdbc:postgresql://localhost:5432/trace_db
  test:
      dataSource:
          dbCreate: update
          url: jdbc:postgresql://localhost:5432/trace_db
  production:
      dataSource:
          dbCreate: update
          url: jdbc:postgresql://localhost:5432/trace_db
          properties:
              jmxEnabled: true
              initialSize: 5
              maxActive: 50
              minIdle: 5
              maxIdle: 25
              maxWait: 10000
              maxAge: 600000
              timeBetweenEvictionRunsMillis: 5000
              minEvictableIdleTimeMillis: 60000
              validationQuery: SELECT 1
              validationQueryTimeout: 3
              validationInterval: 15000
              testOnBorrow: true
              testWhileIdle: true
              testOnReturn: false
              jdbcInterceptors: ConnectionState
              defaultTransactionIsolation: 2 # TRANSACTION_READ_COMMITTED
  </code></pre>
  
  <p>And in my <code>build.gradle</code> I added <code>runtime "postgresql:postgresql:9.4-1207.jdbc4"</code>.</p>
  
  <p>But that gives errors when I run:</p>
  
  <pre><code>ERROR org.apache.tomcat.jdbc.pool.ConnectionPool - Unable to create initial connections of pool.
  java.sql.SQLException: org.postgresql.Driver
  </code></pre>
  
  <p>What have I missed? </p>