private boolean skipSecondPhrase(Column controlColumn, int index) {
    if (isFirstSkip) {
      return false;
    }

    return !controlColumn.isNull(index) && controlColumn.getBoolean(index);
  }
skip the row which don't belong to any window(controlColumn is false or null).
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/execution/operator/window/ConditionWindowManager.java