Esempio n. 1
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  /** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link TableFunctionRel}. */
  public TrimResult trimFields(
      TableFunctionRel tabFun, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
    final RelDataType rowType = tabFun.getRowType();
    final int fieldCount = rowType.getFieldCount();
    List<RelNode> newInputs = new ArrayList<RelNode>();

    for (RelNode input : tabFun.getInputs()) {
      final int inputFieldCount = input.getRowType().getFieldCount();
      BitSet inputFieldsUsed = Util.bitSetBetween(0, inputFieldCount);

      // Create input with trimmed columns.
      final Set<RelDataTypeField> inputExtraFields = Collections.emptySet();
      TrimResult trimResult = trimChildRestore(tabFun, input, inputFieldsUsed, inputExtraFields);
      assert trimResult.right.isIdentity();
      newInputs.add(trimResult.left);
    }

    TableFunctionRel newTabFun = tabFun;
    if (!tabFun.getInputs().equals(newInputs)) {
      newTabFun = tabFun.copy(tabFun.getTraitSet(), newInputs);
    }
    assert newTabFun.getClass() == tabFun.getClass();

    // Always project all fields.
    Mapping mapping = Mappings.createIdentity(fieldCount);
    return new TrimResult(newTabFun, mapping);
  }
Esempio n. 2
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  /** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link TableModificationRel}. */
  public TrimResult trimFields(
      TableModificationRel modifier, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
    // Ignore what consumer wants. We always project all columns.
    Util.discard(fieldsUsed);

    final RelDataType rowType = modifier.getRowType();
    final int fieldCount = rowType.getFieldCount();
    RelNode input = modifier.getChild();

    // We want all fields from the child.
    final int inputFieldCount = input.getRowType().getFieldCount();
    BitSet inputFieldsUsed = Util.bitSetBetween(0, inputFieldCount);

    // Create input with trimmed columns.
    final Set<RelDataTypeField> inputExtraFields = Collections.emptySet();
    TrimResult trimResult = trimChild(modifier, input, inputFieldsUsed, inputExtraFields);
    RelNode newInput = trimResult.left;
    final Mapping inputMapping = trimResult.right;
    if (!inputMapping.isIdentity()) {
      // We asked for all fields. Can't believe that the child decided
      // to permute them!
      throw Util.newInternal("Expected identity mapping, got " + inputMapping);
    }

    TableModificationRel newModifier = modifier;
    if (newInput != input) {
      newModifier = modifier.copy(modifier.getTraitSet(), Collections.singletonList(newInput));
    }
    assert newModifier.getClass() == modifier.getClass();

    // Always project all fields.
    Mapping mapping = Mappings.createIdentity(fieldCount);
    return new TrimResult(newModifier, mapping);
  }
Esempio n. 3
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  /** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link SortRel}. */
  public TrimResult trimFields(SortRel sort, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
    final RelDataType rowType = sort.getRowType();
    final int fieldCount = rowType.getFieldCount();
    final RelCollation collation = sort.getCollation();
    final RelNode input = sort.getChild();

    // We use the fields used by the consumer, plus any fields used as sort
    // keys.
    BitSet inputFieldsUsed = (BitSet) fieldsUsed.clone();
    for (RelFieldCollation field : collation.getFieldCollations()) {
      inputFieldsUsed.set(field.getFieldIndex());
    }

    // Create input with trimmed columns.
    final Set<RelDataTypeField> inputExtraFields = Collections.emptySet();
    TrimResult trimResult = trimChild(sort, input, inputFieldsUsed, inputExtraFields);
    RelNode newInput = trimResult.left;
    final Mapping inputMapping = trimResult.right;

    // If the input is unchanged, and we need to project all columns,
    // there's nothing we can do.
    if (newInput == input && inputMapping.isIdentity() && fieldsUsed.cardinality() == fieldCount) {
      return new TrimResult(sort, Mappings.createIdentity(fieldCount));
    }

    final SortRel newSort =
        sort.copy(sort.getTraitSet(), newInput, RexUtil.apply(inputMapping, collation));
    assert newSort.getClass() == sort.getClass();

    // The result has the same mapping as the input gave us. Sometimes we
    // return fields that the consumer didn't ask for, because the filter
    // needs them for its condition.
    return new TrimResult(newSort, inputMapping);
  }
Esempio n. 4
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 /**
  * Trims unused fields from a relational expression.
  *
  * <p>We presume that all fields of the relational expression are wanted by its consumer, so only
  * trim fields that are not used within the tree.
  *
  * @param root Root node of relational expression
  * @return Trimmed relational expression
  */
 public RelNode trim(RelNode root) {
   final int fieldCount = root.getRowType().getFieldCount();
   final BitSet fieldsUsed = Util.bitSetBetween(0, fieldCount);
   final Set<RelDataTypeField> extraFields = Collections.emptySet();
   final TrimResult trimResult = dispatchTrimFields(root, fieldsUsed, extraFields);
   if (!trimResult.right.isIdentity()) {
     throw new IllegalArgumentException();
   }
   return trimResult.left;
 }
Esempio n. 5
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  /** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link AggregateRel}. */
  public TrimResult trimFields(
      AggregateRel aggregate, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
    // Fields:
    //
    // | sys fields | group fields | agg functions |
    //
    // Two kinds of trimming:
    //
    // 1. If agg rel has system fields but none of these are used, create an
    // agg rel with no system fields.
    //
    // 2. If aggregate functions are not used, remove them.
    //
    // But grouping fields stay, even if they are not used.

    final RelDataType rowType = aggregate.getRowType();

    // Compute which input fields are used.
    BitSet inputFieldsUsed = new BitSet();
    // 1. group fields are always used
    for (int i : Util.toIter(aggregate.getGroupSet())) {
      inputFieldsUsed.set(i);
    }
    // 2. agg functions
    for (AggregateCall aggCall : aggregate.getAggCallList()) {
      for (int i : aggCall.getArgList()) {
        inputFieldsUsed.set(i);
      }
    }

    // Create input with trimmed columns.
    final RelNode input = aggregate.getInput(0);
    final Set<RelDataTypeField> inputExtraFields = Collections.emptySet();
    final TrimResult trimResult = trimChild(aggregate, input, inputFieldsUsed, inputExtraFields);
    final RelNode newInput = trimResult.left;
    final Mapping inputMapping = trimResult.right;

    // If the input is unchanged, and we need to project all columns,
    // there's nothing to do.
    if (input == newInput && fieldsUsed.equals(Util.bitSetBetween(0, rowType.getFieldCount()))) {
      return new TrimResult(aggregate, Mappings.createIdentity(rowType.getFieldCount()));
    }

    // Which agg calls are used by our consumer?
    final int groupCount = aggregate.getGroupSet().cardinality();
    int j = groupCount;
    int usedAggCallCount = 0;
    for (int i = 0; i < aggregate.getAggCallList().size(); i++) {
      if (fieldsUsed.get(j++)) {
        ++usedAggCallCount;
      }
    }

    // Offset due to the number of system fields having changed.
    Mapping mapping =
        Mappings.create(
            MappingType.InverseSurjection, rowType.getFieldCount(), groupCount + usedAggCallCount);

    final BitSet newGroupSet = Mappings.apply(inputMapping, aggregate.getGroupSet());

    // Populate mapping of where to find the fields. System and grouping
    // fields first.
    for (IntPair pair : inputMapping) {
      if (pair.source < groupCount) {
        mapping.set(pair.source, pair.target);
      }
    }

    // Now create new agg calls, and populate mapping for them.
    final List<AggregateCall> newAggCallList = new ArrayList<AggregateCall>();
    j = groupCount;
    for (AggregateCall aggCall : aggregate.getAggCallList()) {
      if (fieldsUsed.get(j)) {
        AggregateCall newAggCall =
            new AggregateCall(
                aggCall.getAggregation(),
                aggCall.isDistinct(),
                Mappings.apply2(inputMapping, aggCall.getArgList()),
                aggCall.getType(),
                aggCall.getName());
        if (newAggCall.equals(aggCall)) {
          newAggCall = aggCall; // immutable -> canonize to save space
        }
        mapping.set(j, groupCount + newAggCallList.size());
        newAggCallList.add(newAggCall);
      }
      ++j;
    }

    RelNode newAggregate =
        new AggregateRel(aggregate.getCluster(), newInput, newGroupSet, newAggCallList);

    assert newAggregate.getClass() == aggregate.getClass();

    return new TrimResult(newAggregate, mapping);
  }
Esempio n. 6
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  /** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link JoinRel}. */
  public TrimResult trimFields(JoinRel join, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
    final RelDataType rowType = join.getRowType();
    final int fieldCount = rowType.getFieldCount();
    final RexNode conditionExpr = join.getCondition();
    final int systemFieldCount = join.getSystemFieldList().size();

    // Add in fields used in the condition.
    BitSet fieldsUsedPlus = (BitSet) fieldsUsed.clone();
    final Set<RelDataTypeField> combinedInputExtraFields =
        new LinkedHashSet<RelDataTypeField>(extraFields);
    RelOptUtil.InputFinder inputFinder =
        new RelOptUtil.InputFinder(fieldsUsedPlus, combinedInputExtraFields);
    conditionExpr.accept(inputFinder);

    // If no system fields are used, we can remove them.
    int systemFieldUsedCount = 0;
    for (int i = 0; i < systemFieldCount; ++i) {
      if (fieldsUsed.get(i)) {
        ++systemFieldUsedCount;
      }
    }
    final int newSystemFieldCount;
    if (systemFieldUsedCount == 0) {
      newSystemFieldCount = 0;
    } else {
      newSystemFieldCount = systemFieldCount;
    }

    int offset = systemFieldCount;
    int changeCount = 0;
    int newFieldCount = newSystemFieldCount;
    List<RelNode> newInputs = new ArrayList<RelNode>(2);
    List<Mapping> inputMappings = new ArrayList<Mapping>();
    List<Integer> inputExtraFieldCounts = new ArrayList<Integer>();
    for (RelNode input : join.getInputs()) {
      final RelDataType inputRowType = input.getRowType();
      final int inputFieldCount = inputRowType.getFieldCount();

      // Compute required mapping.
      BitSet inputFieldsUsed = new BitSet(inputFieldCount);
      for (int bit : Util.toIter(fieldsUsedPlus)) {
        if (bit >= offset && bit < offset + inputFieldCount) {
          inputFieldsUsed.set(bit - offset);
        }
      }

      // If there are system fields, we automatically use the
      // corresponding field in each input.
      if (newSystemFieldCount > 0) {
        // calling with newSystemFieldCount == 0 should be safe but hits
        // http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6222207
        inputFieldsUsed.set(0, newSystemFieldCount);
      }

      // FIXME: We ought to collect extra fields for each input
      // individually. For now, we assume that just one input has
      // on-demand fields.
      Set<RelDataTypeField> inputExtraFields =
          input.getRowType().getField("_extra") == null
              ? Collections.<RelDataTypeField>emptySet()
              : combinedInputExtraFields;
      inputExtraFieldCounts.add(inputExtraFields.size());
      TrimResult trimResult = trimChild(join, input, inputFieldsUsed, inputExtraFields);
      newInputs.add(trimResult.left);
      if (trimResult.left != input) {
        ++changeCount;
      }

      final Mapping inputMapping = trimResult.right;
      inputMappings.add(inputMapping);

      // Move offset to point to start of next input.
      offset += inputFieldCount;
      newFieldCount += inputMapping.getTargetCount() + inputExtraFields.size();
    }

    Mapping mapping = Mappings.create(MappingType.InverseSurjection, fieldCount, newFieldCount);
    for (int i = 0; i < newSystemFieldCount; ++i) {
      mapping.set(i, i);
    }
    offset = systemFieldCount;
    int newOffset = newSystemFieldCount;
    for (int i = 0; i < inputMappings.size(); i++) {
      Mapping inputMapping = inputMappings.get(i);
      for (IntPair pair : inputMapping) {
        mapping.set(pair.source + offset, pair.target + newOffset);
      }
      offset += inputMapping.getSourceCount();
      newOffset += inputMapping.getTargetCount() + inputExtraFieldCounts.get(i);
    }

    if (changeCount == 0 && mapping.isIdentity()) {
      return new TrimResult(join, Mappings.createIdentity(fieldCount));
    }

    // Build new join.
    final RexVisitor<RexNode> shuttle =
        new RexPermuteInputsShuttle(mapping, newInputs.get(0), newInputs.get(1));
    RexNode newConditionExpr = conditionExpr.accept(shuttle);

    final JoinRel newJoin =
        join.copy(join.getTraitSet(), newConditionExpr, newInputs.get(0), newInputs.get(1));

    return new TrimResult(newJoin, mapping);
  }