title: Diff does not detect that index exists
body: <p>When I generate the first diff. The diff file looks correct. It has the tables that we need to create. I run the app, it creates the tables (Oracle), all is good. For validation purposes I run the diff command again, expecting for it to return with no changes. Unfortunately it comes back with changes to the Primary Key Column. If I run the new set of changes and do another diff. It still comes back with the same change logs. It will do this infinitely. </p>
  
  <p>I think that I might be using the wrong dependancies but I am very lost. </p>
  
  <p><strong>POM</strong></p>
  
  <pre><code>&lt;parent&gt;
     &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
     &lt;artifactId&gt;spring-boot-starter-parent&lt;/artifactId&gt;
     &lt;version&gt;2.2.1.RELEASE&lt;/version&gt;
     &lt;relativePath/&gt; &lt;!-- lookup parent from repository --&gt;
  &lt;/parent&gt;
  &lt;dependencies&gt;
     &lt;dependency&gt;
        &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
        &lt;artifactId&gt;spring-boot-starter-web&lt;/artifactId&gt;
     &lt;/dependency&gt;
     &lt;dependency&gt;
        &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
        &lt;artifactId&gt;spring-boot-starter-data-jpa&lt;/artifactId&gt;
     &lt;/dependency&gt;
     &lt;dependency&gt;
        &lt;groupId&gt;org.projectlombok&lt;/groupId&gt;
        &lt;artifactId&gt;lombok&lt;/artifactId&gt;
        &lt;optional&gt;true&lt;/optional&gt;
     &lt;/dependency&gt;
     &lt;dependency&gt;
        &lt;groupId&gt;com.oracle.database&lt;/groupId&gt;
        &lt;artifactId&gt;ojdbc7&lt;/artifactId&gt;
        &lt;version&gt;12.1.0.1&lt;/version&gt;
     &lt;/dependency&gt;
     &lt;dependency&gt;
        &lt;groupId&gt;org.liquibase&lt;/groupId&gt;
        &lt;artifactId&gt;liquibase-core&lt;/artifactId&gt;
     &lt;/dependency&gt;
  &lt;/dependencies&gt;
  ...
  &lt;plugin&gt;
      &lt;groupId&gt;org.liquibase&lt;/groupId&gt;
      &lt;artifactId&gt;liquibase-maven-plugin&lt;/artifactId&gt;
      &lt;version&gt;3.8.1&lt;/version&gt;
      &lt;configuration&gt;
          &lt;propertyFile&gt;/src/main/resources/liquibase.properties&lt;/propertyFile&gt;
      &lt;/configuration&gt;
      &lt;dependencies&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.liquibase.ext&lt;/groupId&gt;
              &lt;artifactId&gt;liquibase-hibernate5&lt;/artifactId&gt;
              &lt;version&gt;3.6&lt;/version&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-data-jpa&lt;/artifactId&gt;
              &lt;version&gt;2.2.1.RELEASE&lt;/version&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;javax.validation&lt;/groupId&gt;
              &lt;artifactId&gt;validation-api&lt;/artifactId&gt;
              &lt;version&gt;2.0.1.Final&lt;/version&gt;
          &lt;/dependency&gt;
      &lt;/dependencies&gt;
  &lt;/plugin&gt;
  </code></pre>
  
  <p><strong>Table Creation Change Set</strong></p>
  
  <pre><code>databaseChangeLog:
  - changeSet:
      id: 1576786181941-1
      author: Stackoverflow (generated)
      changes:
      - createTable:
          columns:
          - column:
              constraints:
                primaryKey: true
                primaryKeyName: usernamePK
              name: username
              type: VARCHAR2(32 CHAR)
          - column:
              constraints:
                nullable: false
              name: description
              type: VARCHAR2(1000 CHAR)
          - column:
              constraints:
                nullable: false
              name: status
              type: VARCHAR2(200 CHAR)
          tableName: users
  </code></pre>
  
  <p><strong>Diff that is always created</strong></p>
  
  <pre><code>databaseChangeLog:
  - changeSet:
      id: 1578435590163-1
      author: Stackoverflow (generated)
      changes:
      - dropPrimaryKey:
          tableName: users
  - changeSet:
      id: 1578435590163-2
      author: Stackoverflow (generated)
      changes:
      - createIndex:
          columns:
          - column:
              name: username
          indexName: IX_usersPK
          tableName: users
          unique: true
  - changeSet:
      id: 1578435590163-3
      author: Stackoverflow (generated)
      changes:
      - addPrimaryKey:
          columnNames: username
          constraintName: usersPK
          forIndexName: IX_usersPK
          tableName: users
  </code></pre>
  
  <p><strong>liquibase properties</strong></p>
  
  <p><code>referenceUrl=hibernate:spring:com.example?dialect=org.hibernate.dialect.Oracle12cDialect&amp;hibernate.physical_naming_strategy=org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy&amp;hibernate.implicit_naming_strategy=org.springframework.boot.orm.jpa.hibernate.SpringImplicitNamingStrategy</code></p>