How to use

setLeftRightBitmaps

method

in

org.apache.calcite.rel.metadata.RelMdUtil

/**
 * Computes the population size for a set of keys returned from a join
 *
 * @param joinRel  the join rel
 * @param groupKey keys to compute the population for
 * @return computed population size
 */
public static Double getJoinPopulationSize(RelMetadataQuery mq,
  RelNode joinRel, ImmutableBitSet groupKey) {
 ImmutableBitSet.Builder leftMask = ImmutableBitSet.builder();
 ImmutableBitSet.Builder rightMask = ImmutableBitSet.builder();
 RelNode left = joinRel.getInputs().get(0);
 RelNode right = joinRel.getInputs().get(1);
 // separate the mask into masks for the left and right
 RelMdUtil.setLeftRightBitmaps(
   groupKey, leftMask, rightMask, left.getRowType().getFieldCount());
 Double population =
   NumberUtil.multiply(
     mq.getPopulationSize(left, leftMask.build()),
     mq.getPopulationSize(right, rightMask.build()));
 return numDistinctVals(population, mq.getRowCount(joinRel));
}

/**
 * Computes the population size for a set of keys returned from a join
 *
 * @param joinRel  the join rel
 * @param groupKey keys to compute the population for
 * @return computed population size
 */
public static Double getJoinPopulationSize(RelMetadataQuery mq,
  RelNode joinRel, ImmutableBitSet groupKey) {
 ImmutableBitSet.Builder leftMask = ImmutableBitSet.builder();
 ImmutableBitSet.Builder rightMask = ImmutableBitSet.builder();
 RelNode left = joinRel.getInputs().get(0);
 RelNode right = joinRel.getInputs().get(1);
 // separate the mask into masks for the left and right
 RelMdUtil.setLeftRightBitmaps(
   groupKey, leftMask, rightMask, left.getRowType().getFieldCount());
 Double population =
   NumberUtil.multiply(
     mq.getPopulationSize(left, leftMask.build()),
     mq.getPopulationSize(right, rightMask.build()));
 return numDistinctVals(population, mq.getRowCount(joinRel));
}

RelNode right = joinRel.getInputs().get(1);
RelMdUtil.setLeftRightBitmaps(
  groupKey,
  leftMask,

RelNode right = joinRel.getInputs().get(1);
RelMdUtil.setLeftRightBitmaps(
  groupKey,
  leftMask,