protected DatabaseMetaData getDatabaseMetaData() throws SQLException {
    if (databaseMetaData == null) {
      databaseMetaData = connection.getMetaData();
    }

    return databaseMetaData;
  }
Map SQL datatype to Java Class type

@param type  SQL datatype
@return Java class or null if no mapping found
ambari-server/src/main/java/org/apache/ambari/server/orm/DBAccessorImpl.java