private int generateHashSetResults(VectorizedRowBatch batch,
      int[] allMatches, int allMatchCount) {
    int numSel = 0;
    // Generate result within big table batch itself.
    for (int i = 0; i < allMatchCount; i++) {
      int batchIndex = this.allMatches[i];
      // Use the big table row as output.
      batch.selected[numSel++] = batchIndex;
    }
    return numSel;
  }
Generate the matching anti join output results of a vectorized row batch.

@param batch
         The big table batch.
@param allMatches
         A subset of the rows of the batch that are matches.
@param allMatchCount
         Number of matches in allMatches.
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/mapjoin/VectorMapJoinAntiJoinGenerateResultOperator.java