@Explain(displayName = "buckets included", explainLevels = { Level.EXTENDED })
  public String getIncludedBucketExplain() {
    if (this.includedBuckets == null) {
      return null;
    }

    StringBuilder sb = new StringBuilder();
    sb.append("[");
    for (int i = 0; i < this.includedBuckets.size(); i++) {
      if (this.includedBuckets.get(i)) {
        sb.append(i);
        sb.append(',');
      }
    }
    sb.append(String.format("] of %d", numBuckets));
    return sb.toString();
  }
A boolean variable set to true by the semantic analyzer only in case of the analyze command.
ql/src/java/org/apache/hadoop/hive/ql/plan/TableScanDesc.java