public static void setReadAllColumns(Configuration conf) {
    conf.setBoolean(READ_ALL_COLUMNS, true);
    setReadColumnIDConf(conf, READ_COLUMN_IDS_CONF_STR_DEFAULT);
  }
Sets the <em>READ_ALL_COLUMNS</em> flag and removes any previously
set column ids.
serde/src/java/org/apache/hadoop/hive/serde2/ColumnProjectionUtils.java