static void compareAgainstPostgres(String dbType) throws Exception {
    LOG.info("Comparing {} against Postgres", dbType);
    DDL postgres = DDLTestUtils.getDdl("Postgres");
    DDL other = DDLTestUtils.getDdl(dbType);
    List<String> diffs = compareDdls(postgres, other);
    if (diffs.isEmpty()) {
      LOG.info("Compare OK.");
    }
    else {
      LOG.info("{} differences found:", diffs.size());
      for (String diff: diffs) { LOG.info(diff); }
      StringBuilder buffer = new StringBuilder();
      buffer.append("Found ").append(diffs.size()).append(" differences when comparing ").append(
          other).append(" against Postgres:").append(System.lineSeparator()).append(
              StringUtils.join(diffs, System.lineSeparator()));

      Assert.fail(buffer.toString());
    }
  }
To verify if DDL have certain characteristics:
<ul>
  <li>There are no unnamed constraints</li>
  <li>Alter tables are only used in exceptional cases</li>
  <li>Table and constraint name lenghts doesn't exceed 30 (a restriction imposed by Oracle)</li>
</ul>
ambari-server/src/test/java/org/apache/ambari/server/orm/db/DDLTests.java