How to use

numDistinctVals

method

in

org.apache.calcite.rel.metadata.RelMdUtil

public Double visitLiteral(RexLiteral literal) {
 return numDistinctVals(1.0, mq.getRowCount(rel));
}

public Double visitLiteral(RexLiteral literal) {
 return numDistinctVals(1.0, mq.getRowCount(rel));
}

public Double getDistinctRowCount(Values rel, RelMetadataQuery mq,
  ImmutableBitSet groupKey, RexNode predicate) {
 if (predicate == null || predicate.isAlwaysTrue()) {
  if (groupKey.isEmpty()) {
   return 1D;
  }
 }
 double selectivity = RelMdUtil.guessSelectivity(predicate);
 // assume half the rows are duplicates
 double nRows = rel.estimateRowCount(mq) / 2;
 return RelMdUtil.numDistinctVals(nRows, nRows * selectivity);
}

public Double getDistinctRowCount(Values rel, RelMetadataQuery mq,
  ImmutableBitSet groupKey, RexNode predicate) {
 if (predicate == null || predicate.isAlwaysTrue()) {
  if (groupKey.isEmpty()) {
   return 1D;
  }
 }
 double selectivity = RelMdUtil.guessSelectivity(predicate);
 // assume half the rows are duplicates
 double nRows = rel.estimateRowCount(mq) / 2;
 return RelMdUtil.numDistinctVals(nRows, nRows * selectivity);
}

public Double visitInputRef(RexInputRef var) {
 int index = var.getIndex();
 ImmutableBitSet col = ImmutableBitSet.of(index);
 Double distinctRowCount =
   mq.getDistinctRowCount(rel.getInput(), col, null);
 if (distinctRowCount == null) {
  return null;
 } else {
  return numDistinctVals(distinctRowCount, mq.getRowCount(rel));
 }
}

public Double visitInputRef(RexInputRef var) {
 int index = var.getIndex();
 ImmutableBitSet col = ImmutableBitSet.of(index);
 Double distinctRowCount =
   mq.getDistinctRowCount(rel.getInput(), col, null);
 if (distinctRowCount == null) {
  return null;
 } else {
  return numDistinctVals(distinctRowCount, mq.getRowCount(rel));
 }
}

return numDistinctVals(distinctRowCount, rowCount);

return numDistinctVals(distinctRowCount, rowCount);

/**
 * 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));
}

public Double getPopulationSize(Project rel, RelMetadataQuery mq,
  ImmutableBitSet groupKey) {
 ImmutableBitSet.Builder baseCols = ImmutableBitSet.builder();
 ImmutableBitSet.Builder projCols = ImmutableBitSet.builder();
 List<RexNode> projExprs = rel.getProjects();
 RelMdUtil.splitCols(projExprs, groupKey, baseCols, projCols);
 Double population =
   mq.getPopulationSize(rel.getInput(), baseCols.build());
 if (population == null) {
  return null;
 }
 // No further computation required if the projection expressions are
 // all column references
 if (projCols.cardinality() == 0) {
  return population;
 }
 for (int bit : projCols.build()) {
  Double subRowCount =
    RelMdUtil.cardOfProjExpr(mq, rel, projExprs.get(bit));
  if (subRowCount == null) {
   return null;
  }
  population *= subRowCount;
 }
 // REVIEW zfong 6/22/06 - Broadbase did not have the call to
 // numDistinctVals.  This is needed; otherwise, population can be
 // larger than the number of rows in the RelNode.
 return RelMdUtil.numDistinctVals(population, mq.getRowCount(rel));
}

public Double getPopulationSize(Project rel, RelMetadataQuery mq,
  ImmutableBitSet groupKey) {
 ImmutableBitSet.Builder baseCols = ImmutableBitSet.builder();
 ImmutableBitSet.Builder projCols = ImmutableBitSet.builder();
 List<RexNode> projExprs = rel.getProjects();
 RelMdUtil.splitCols(projExprs, groupKey, baseCols, projCols);
 Double population =
   mq.getPopulationSize(rel.getInput(), baseCols.build());
 if (population == null) {
  return null;
 }
 // No further computation required if the projection expressions are
 // all column references
 if (projCols.cardinality() == 0) {
  return population;
 }
 for (int bit : projCols.build()) {
  Double subRowCount =
    RelMdUtil.cardOfProjExpr(mq, rel, projExprs.get(bit));
  if (subRowCount == null) {
   return null;
  }
  population *= subRowCount;
 }
 // REVIEW zfong 6/22/06 - Broadbase did not have the call to
 // numDistinctVals.  This is needed; otherwise, population can be
 // larger than the number of rows in the RelNode.
 return RelMdUtil.numDistinctVals(population, mq.getRowCount(rel));
}

return RelMdUtil.numDistinctVals(distRowCount, mq.getRowCount(joinRel));

return RelMdUtil.numDistinctVals(distRowCount, mq.getRowCount(joinRel));

return RelMdUtil.numDistinctVals(distinctRowCount, mq.getRowCount(rel));

return RelMdUtil.numDistinctVals(distinctRowCount, mq.getRowCount(rel));