Пример #1
0
 /**
  * Creates a relational expression which projects an array of expressions, and optionally
  * optimizes.
  *
  * <p>The result may not be a {@link ProjectRel}. If the projection is trivial, <code>child</code>
  * is returned directly; and future versions may return other formulations of expressions, such as
  * {@link CalcRel}.
  *
  * @param child input relational expression
  * @param exprs list of expressions for the input columns
  * @param fieldNames aliases of the expressions, or null to generate
  * @param optimize Whether to return <code>child</code> unchanged if the projections are trivial.
  */
 public static RelNode createProject(
     RelNode child, List<RexNode> exprs, List<String> fieldNames, boolean optimize) {
   final RelOptCluster cluster = child.getCluster();
   final RexProgram program =
       RexProgram.create(child.getRowType(), exprs, null, fieldNames, cluster.getRexBuilder());
   final List<RelCollation> collationList = program.getCollations(child.getCollationList());
   if (DeprecateProjectAndFilter) {
     return new CalcRel(
         cluster, child.getTraitSet(), child, program.getOutputRowType(), program, collationList);
   } else {
     final RelDataType rowType =
         RexUtil.createStructType(cluster.getTypeFactory(), exprs, fieldNames);
     if (optimize && RemoveTrivialProjectRule.isIdentity(exprs, rowType, child.getRowType())) {
       return child;
     }
     return new ProjectRel(
         cluster,
         cluster.traitSetOf(
             collationList.isEmpty() ? RelCollationImpl.EMPTY : collationList.get(0)),
         child,
         exprs,
         rowType,
         ProjectRelBase.Flags.Boxed);
   }
 }
Пример #2
0
 /**
  * Creates a relational expression which projects an array of expressions, and optionally
  * optimizes.
  *
  * <p>The result may not be a {@link ProjectRel}. If the projection is trivial, <code>child</code>
  * is returned directly; and future versions may return other formulations of expressions, such as
  * {@link CalcRel}.
  *
  * @param child input relational expression
  * @param exprs list of expressions for the input columns
  * @param fieldNames aliases of the expressions, or null to generate
  * @param optimize Whether to return <code>child</code> unchanged if the projections are trivial.
  */
 public static RelNode createProject(
     RelNode child, List<RexNode> exprs, List<String> fieldNames, boolean optimize) {
   final RelOptCluster cluster = child.getCluster();
   final RexProgram program =
       RexProgram.create(child.getRowType(), exprs, null, fieldNames, cluster.getRexBuilder());
   final List<RelCollation> collationList = program.getCollations(child.getCollationList());
   if (DEPRECATE_PROJECT_AND_FILTER) {
     return new CalcRel(
         cluster, child.getTraitSet(), child, program.getOutputRowType(), program, collationList);
   } else {
     final RelDataType rowType =
         RexUtil.createStructType(
             cluster.getTypeFactory(),
             exprs,
             fieldNames == null
                 ? null
                 : SqlValidatorUtil.uniquify(fieldNames, SqlValidatorUtil.F_SUGGESTER));
     if (optimize && RemoveTrivialProjectRule.isIdentity(exprs, rowType, child.getRowType())) {
       return child;
     }
     return new ProjectRel(
         cluster,
         cluster.traitSetOf(
             collationList.isEmpty() ? RelCollationImpl.EMPTY : collationList.get(0)),
         child,
         exprs,
         rowType,
         ProjectRelBase.Flags.BOXED);
   }
 }
Пример #3
0
 /**
  * Creates a relational expression which permutes the output fields of a relational expression
  * according to a permutation.
  *
  * <p>Optimizations:
  *
  * <ul>
  *   <li>If the relational expression is a {@link CalcRel} or {@link ProjectRel} which is already
  *       acting as a permutation, combines the new permutation with the old;
  *   <li>If the permutation is the identity, returns the original relational expression.
  * </ul>
  *
  * <p>If a permutation is combined with its inverse, these optimizations would combine to remove
  * them both.
  *
  * @param rel Relational expression
  * @param permutation Permutation to apply to fields
  * @param fieldNames Field names; if null, or if a particular entry is null, the name of the
  *     permuted field is used
  * @return relational expression which permutes its input fields
  */
 public static RelNode permute(RelNode rel, Permutation permutation, List<String> fieldNames) {
   if (permutation.isIdentity()) {
     return rel;
   }
   if (rel instanceof CalcRel) {
     CalcRel calcRel = (CalcRel) rel;
     Permutation permutation1 = calcRel.getProgram().getPermutation();
     if (permutation1 != null) {
       Permutation permutation2 = permutation.product(permutation1);
       return permute(rel, permutation2, null);
     }
   }
   if (rel instanceof ProjectRel) {
     Permutation permutation1 = ((ProjectRel) rel).getPermutation();
     if (permutation1 != null) {
       Permutation permutation2 = permutation.product(permutation1);
       return permute(rel, permutation2, null);
     }
   }
   final List<RelDataType> outputTypeList = new ArrayList<RelDataType>();
   final List<String> outputNameList = new ArrayList<String>();
   final List<RexNode> exprList = new ArrayList<RexNode>();
   final List<RexLocalRef> projectRefList = new ArrayList<RexLocalRef>();
   final List<RelDataTypeField> fields = rel.getRowType().getFieldList();
   for (int i = 0; i < permutation.getTargetCount(); i++) {
     int target = permutation.getTarget(i);
     final RelDataTypeField targetField = fields.get(target);
     outputTypeList.add(targetField.getType());
     outputNameList.add(
         ((fieldNames == null) || (fieldNames.size() <= i) || (fieldNames.get(i) == null))
             ? targetField.getName()
             : fieldNames.get(i));
     exprList.add(rel.getCluster().getRexBuilder().makeInputRef(fields.get(i).getType(), i));
     final int source = permutation.getSource(i);
     projectRefList.add(new RexLocalRef(source, fields.get(source).getType()));
   }
   final RexProgram program =
       new RexProgram(
           rel.getRowType(),
           exprList,
           projectRefList,
           null,
           rel.getCluster().getTypeFactory().createStructType(outputTypeList, outputNameList));
   return new CalcRel(
       rel.getCluster(),
       rel.getTraitSet(),
       rel,
       program.getOutputRowType(),
       program,
       Collections.<RelCollation>emptyList());
 }
Пример #4
0
  public void onMatch(RelOptRuleCall call) {
    assert matches(call);
    final JoinRel join = (JoinRel) call.rels[0];
    final List<Integer> leftKeys = new ArrayList<Integer>();
    final List<Integer> rightKeys = new ArrayList<Integer>();
    RelNode right = join.getRight();
    final RelNode left = join.getLeft();
    RexNode remainingCondition =
        RelOptUtil.splitJoinCondition(left, right, join.getCondition(), leftKeys, rightKeys);
    assert leftKeys.size() == rightKeys.size();
    final List<CorrelatorRel.Correlation> correlationList =
        new ArrayList<CorrelatorRel.Correlation>();
    if (leftKeys.size() > 0) {
      final RelOptCluster cluster = join.getCluster();
      final RexBuilder rexBuilder = cluster.getRexBuilder();
      int k = 0;
      RexNode condition = null;
      for (Integer leftKey : leftKeys) {
        Integer rightKey = rightKeys.get(k++);
        final String dyn_inIdStr = cluster.getQuery().createCorrel();
        final int dyn_inId = RelOptQuery.getCorrelOrdinal(dyn_inIdStr);

        // Create correlation to say 'each row, set variable #id
        // to the value of column #leftKey'.
        correlationList.add(new CorrelatorRel.Correlation(dyn_inId, leftKey));
        condition =
            RelOptUtil.andJoinFilters(
                rexBuilder,
                condition,
                rexBuilder.makeCall(
                    SqlStdOperatorTable.equalsOperator,
                    rexBuilder.makeInputRef(
                        right.getRowType().getFieldList().get(rightKey).getType(), rightKey),
                    rexBuilder.makeCorrel(
                        left.getRowType().getFieldList().get(leftKey).getType(), dyn_inIdStr)));
      }
      right = CalcRel.createFilter(right, condition);
    }
    RelNode newRel =
        new CorrelatorRel(
            join.getCluster(),
            left,
            right,
            remainingCondition,
            correlationList,
            join.getJoinType());
    call.transformTo(newRel);
  }
Пример #5
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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);
  }
Пример #6
0
  /** 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);
  }
Пример #7
0
 private void bindDeferred(JavaFrame frame, final RelNode rel) {
   final StatementList statementList = getStatementList();
   if (frame.bind == null) {
     // this relational expression has not bound itself, so we presume
     // that we can call its implementSelf() method
     if (!(rel instanceof JavaSelfRel)) {
       throw Util.newInternal(
           "In order to bind-deferred, a "
               + "relational expression must implement JavaSelfRel: "
               + rel);
     }
     final JavaSelfRel selfRel = (JavaSelfRel) rel;
     LazyBind lazyBind =
         new LazyBind(
             newVariable(),
             statementList,
             getTypeFactory(),
             rel.getRowType(),
             new VariableInitializerThunk() {
               public VariableInitializer getInitializer() {
                 return selfRel.implementSelf(JavaRelImplementor.this);
               }
             });
     bind(rel, lazyBind);
   } else if ((frame.bind instanceof LazyBind)
       && (((LazyBind) frame.bind).statementList != statementList)) {
     // Frame is already bound, but to a variable declared in a different
     // scope. Re-bind it.
     final LazyBind lazyBind = (LazyBind) frame.bind;
     lazyBind.statementList = statementList;
     lazyBind.bound = false;
   }
 }
Пример #8
0
 /**
  * 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;
 }
Пример #9
0
 /**
  * Trims the fields of an input relational expression.
  *
  * @param rel Relational expression
  * @param input Input relational expression, whose fields to trim
  * @param fieldsUsed Bitmap of fields needed by the consumer
  * @return New relational expression and its field mapping
  */
 protected TrimResult trimChild(
     RelNode rel, RelNode input, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
   Util.discard(rel);
   if (input.getClass().getName().endsWith("MedMdrClassExtentRel")) {
     // MedMdrJoinRule cannot handle Join of Project of
     // MedMdrClassExtentRel, only naked MedMdrClassExtentRel.
     // So, disable trimming.
     fieldsUsed = Util.bitSetBetween(0, input.getRowType().getFieldCount());
   }
   return dispatchTrimFields(input, fieldsUsed, extraFields);
 }
Пример #10
0
 /**
  * Creates a relational expression which projects the output fields of a relational expression
  * according to a partial mapping.
  *
  * <p>A partial mapping is weaker than a permutation: every target has one source, but a source
  * may have 0, 1 or more than one targets. Usually the result will have fewer fields than the
  * source, unless some source fields are projected multiple times.
  *
  * <p>This method could optimize the result as {@link #permute} does, but does not at present.
  *
  * @param rel Relational expression
  * @param mapping Mapping from source fields to target fields. The mapping type must obey the
  *     constaints {@link MappingType#isMandatorySource()} and {@link
  *     MappingType#isSingleSource()}, as does {@link MappingType#InverseFunction}.
  * @param fieldNames Field names; if null, or if a particular entry is null, the name of the
  *     permuted field is used
  * @return relational expression which projects a subset of the input fields
  */
 public static RelNode projectMapping(RelNode rel, Mapping mapping, List<String> fieldNames) {
   assert mapping.getMappingType().isSingleSource();
   assert mapping.getMappingType().isMandatorySource();
   if (mapping.isIdentity()) {
     return rel;
   }
   final List<RelDataType> outputTypeList = new ArrayList<RelDataType>();
   final List<String> outputNameList = new ArrayList<String>();
   final List<RexNode> exprList = new ArrayList<RexNode>();
   final List<RexLocalRef> projectRefList = new ArrayList<RexLocalRef>();
   final List<RelDataTypeField> fields = rel.getRowType().getFieldList();
   for (int i = 0; i < fields.size(); i++) {
     final RelDataTypeField field = fields.get(i);
     exprList.add(rel.getCluster().getRexBuilder().makeInputRef(field.getType(), i));
   }
   for (int i = 0; i < mapping.getTargetCount(); i++) {
     int source = mapping.getSource(i);
     final RelDataTypeField sourceField = fields.get(source);
     outputTypeList.add(sourceField.getType());
     outputNameList.add(
         ((fieldNames == null) || (fieldNames.size() <= i) || (fieldNames.get(i) == null))
             ? sourceField.getName()
             : fieldNames.get(i));
     projectRefList.add(new RexLocalRef(source, sourceField.getType()));
   }
   final RexProgram program =
       new RexProgram(
           rel.getRowType(),
           exprList,
           projectRefList,
           null,
           rel.getCluster().getTypeFactory().createStructType(outputTypeList, outputNameList));
   return new CalcRel(
       rel.getCluster(),
       rel.getTraitSet(),
       rel,
       program.getOutputRowType(),
       program,
       Collections.<RelCollation>emptyList());
 }
Пример #11
0
 /**
  * Returns the index of the first field in <code>rel</code> which comes from its <code>ordinal
  * </code>th input.
  *
  * <p>For example, if rel joins T0(A,B,C) to T1(D,E), then countFields(0,rel) yields 0, and
  * countFields(1,rel) yields 3.
  */
 private int computeFieldOffset(RelNode rel, int ordinal) {
   if (ordinal == 0) {
     // short-circuit for the common case
     return 0;
   }
   int fieldOffset = 0;
   final List<RelNode> inputs = rel.getInputs();
   for (int i = 0; i < ordinal; i++) {
     RelNode input = inputs.get(i);
     fieldOffset += input.getRowType().getFieldList().size();
   }
   return fieldOffset;
 }
Пример #12
0
 /**
  * Invokes {@link #trimFields}, or the appropriate method for the type of the rel parameter, using
  * multi-method dispatch.
  *
  * @param rel Relational expression
  * @param fieldsUsed Bitmap of fields needed by the consumer
  * @return New relational expression and its field mapping
  */
 protected final TrimResult dispatchTrimFields(
     RelNode rel, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
   final TrimResult trimResult = trimFieldsDispatcher.invoke(rel, fieldsUsed, extraFields);
   final RelNode newRel = trimResult.left;
   final Mapping mapping = trimResult.right;
   final int fieldCount = rel.getRowType().getFieldCount();
   assert mapping.getSourceCount() == fieldCount
       : "source: " + mapping.getSourceCount() + " != " + fieldCount;
   final int newFieldCount = newRel.getRowType().getFieldCount();
   assert mapping.getTargetCount() + extraFields.size() == newFieldCount
       : "target: "
           + mapping.getTargetCount()
           + " + "
           + extraFields.size()
           + " != "
           + newFieldCount;
   if (Bug.TodoFixed) assert newFieldCount > 0 : "rel has no fields after trim: " + rel;
   if (newRel.equals(rel)) {
     return new TrimResult(rel, mapping);
   }
   return trimResult;
 }
Пример #13
0
  /**
   * Returns a relational expression which has the same fields as the underlying expression, but the
   * fields have different names.
   *
   * @param rel Relational expression
   * @param fieldNames Field names
   * @return Renamed relational expression
   */
  public static RelNode createRename(RelNode rel, List<String> fieldNames) {
    final List<RelDataTypeField> fields = rel.getRowType().getFieldList();
    assert fieldNames.size() == fields.size();
    final List<Pair<RexNode, String>> refs =
        new AbstractList<Pair<RexNode, String>>() {
          public int size() {
            return fields.size();
          }

          public Pair<RexNode, String> get(int index) {
            return RexInputRef.of2(index, fields);
          }
        };
    return createProject(rel, refs, true);
  }
Пример #14
0
  /**
   * Declares a variable, and binds it lazily, so it only gets initialized if it is actually used.
   *
   * @return the Variable so declared
   */
  public Variable bind(
      RelNode rel, StatementList statementList, final VariableInitializer initializer) {
    VariableInitializerThunk thunk =
        new VariableInitializerThunk() {
          public VariableInitializer getInitializer() {
            return initializer;
          }
        };

    Variable variable = newVariable();
    LazyBind bind =
        new LazyBind(variable, statementList, getTypeFactory(), rel.getRowType(), thunk);
    bind(rel, bind);
    return bind.getVariable();
  }
Пример #15
0
 /**
  * Creates a relational expression which filters according to a given condition, returning the
  * same fields as its input.
  *
  * @param child Child relational expression
  * @param condition Condition
  * @return Relational expression
  */
 public static RelNode createFilter(RelNode child, RexNode condition) {
   if (DeprecateProjectAndFilter) {
     final RelOptCluster cluster = child.getCluster();
     RexProgramBuilder builder =
         new RexProgramBuilder(child.getRowType(), cluster.getRexBuilder());
     builder.addIdentity();
     builder.addCondition(condition);
     final RexProgram program = builder.getProgram();
     return new CalcRel(
         cluster,
         child.getTraitSet(),
         child,
         program.getOutputRowType(),
         program,
         Collections.<RelCollation>emptyList());
   } else {
     return new FilterRel(child.getCluster(), child, condition);
   }
 }
Пример #16
0
 /**
  * Trims a child relational expression, then adds back a dummy project to restore the fields that
  * were removed.
  *
  * <p>Sounds pointless? It causes unused fields to be removed further down the tree (towards the
  * leaves), but it ensure that the consuming relational expression continues to see the same
  * fields.
  *
  * @param rel Relational expression
  * @param input Input relational expression, whose fields to trim
  * @param fieldsUsed Bitmap of fields needed by the consumer
  * @return New relational expression and its field mapping
  */
 protected TrimResult trimChildRestore(
     RelNode rel, RelNode input, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
   TrimResult trimResult = trimChild(rel, input, fieldsUsed, extraFields);
   if (trimResult.right.isIdentity()) {
     return trimResult;
   }
   final RelDataType rowType = input.getRowType();
   List<RelDataTypeField> fieldList = rowType.getFieldList();
   final List<RexNode> exprList = new ArrayList<RexNode>();
   final List<String> nameList = rowType.getFieldNames();
   RexBuilder rexBuilder = rel.getCluster().getRexBuilder();
   assert trimResult.right.getSourceCount() == fieldList.size();
   for (int i = 0; i < fieldList.size(); i++) {
     int source = trimResult.right.getTargetOpt(i);
     RelDataTypeField field = fieldList.get(i);
     exprList.add(
         source < 0
             ? rexBuilder.makeZeroLiteral(field.getType())
             : rexBuilder.makeInputRef(field.getType(), source));
   }
   RelNode project = CalcRel.createProject(trimResult.left, exprList, nameList);
   return new TrimResult(project, Mappings.createIdentity(fieldList.size()));
 }
Пример #17
0
  /** Variant of {@link #trimFields(RelNode, BitSet, Set)} for {@link ProjectRel}. */
  public TrimResult trimFields(
      ProjectRel project, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
    final RelDataType rowType = project.getRowType();
    final int fieldCount = rowType.getFieldCount();
    final RelNode input = project.getChild();
    final RelDataType inputRowType = input.getRowType();

    // Which fields are required from the input?
    BitSet inputFieldsUsed = new BitSet(inputRowType.getFieldCount());
    final Set<RelDataTypeField> inputExtraFields = new LinkedHashSet<RelDataTypeField>(extraFields);
    RelOptUtil.InputFinder inputFinder =
        new RelOptUtil.InputFinder(inputFieldsUsed, inputExtraFields);
    for (Ord<RexNode> ord : Ord.zip(project.getProjects())) {
      if (fieldsUsed.get(ord.i)) {
        ord.e.accept(inputFinder);
      }
    }

    // Create input with trimmed columns.
    TrimResult trimResult = trimChild(project, 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 && fieldsUsed.cardinality() == fieldCount) {
      return new TrimResult(project, Mappings.createIdentity(fieldCount));
    }

    // Some parts of the system can't handle rows with zero fields, so
    // pretend that one field is used.
    if (fieldsUsed.cardinality() == 0) {
      final Mapping mapping = Mappings.create(MappingType.InverseSurjection, fieldCount, 1);
      final RexLiteral expr =
          project.getCluster().getRexBuilder().makeExactLiteral(BigDecimal.ZERO);
      RelDataType newRowType =
          project
              .getCluster()
              .getTypeFactory()
              .createStructType(
                  Collections.singletonList(expr.getType()), Collections.singletonList("DUMMY"));
      ProjectRel newProject =
          new ProjectRel(
              project.getCluster(),
              project.getCluster().traitSetOf(RelCollationImpl.EMPTY),
              newInput,
              Collections.<RexNode>singletonList(expr),
              newRowType,
              project.getFlags());
      return new TrimResult(newProject, mapping);
    }

    // Build new project expressions, and populate the mapping.
    List<RexNode> newProjectExprList = new ArrayList<RexNode>();
    final RexVisitor<RexNode> shuttle = new RexPermuteInputsShuttle(inputMapping, newInput);
    final Mapping mapping =
        Mappings.create(MappingType.InverseSurjection, fieldCount, fieldsUsed.cardinality());
    for (Ord<RexNode> ord : Ord.zip(project.getProjects())) {
      if (fieldsUsed.get(ord.i)) {
        mapping.set(ord.i, newProjectExprList.size());
        RexNode newProjectExpr = ord.e.accept(shuttle);
        newProjectExprList.add(newProjectExpr);
      }
    }

    final RelDataType newRowType =
        project
            .getCluster()
            .getTypeFactory()
            .createStructType(Mappings.apply3(mapping, rowType.getFieldList()));

    final List<RelCollation> newCollations =
        RexUtil.apply(inputMapping, project.getCollationList());

    final RelNode newProject;
    if (RemoveTrivialProjectRule.isIdentity(
        newProjectExprList, newRowType, newInput.getRowType())) {
      // The new project would be the identity. It is equivalent to return
      // its child.
      newProject = newInput;
    } else {
      newProject =
          new ProjectRel(
              project.getCluster(),
              project
                  .getCluster()
                  .traitSetOf(
                      newCollations.isEmpty() ? RelCollationImpl.EMPTY : newCollations.get(0)),
              newInput,
              newProjectExprList,
              newRowType,
              project.getFlags());
      assert newProject.getClass() == project.getClass();
    }
    return new TrimResult(newProject, mapping);
  }
Пример #18
0
 /**
  * Visit method, per {@link org.eigenbase.util.ReflectiveVisitor}.
  *
  * <p>This method is invoked reflectively, so there may not be any apparent calls to it. The class
  * (or derived classes) may contain overloads of this method with more specific types for the
  * {@code rel} parameter.
  *
  * <p>Returns a pair: the relational expression created, and the mapping between the original
  * fields and the fields of the newly created relational expression.
  *
  * @param rel Relational expression
  * @param fieldsUsed Fields needed by the consumer
  * @return relational expression and mapping
  */
 public TrimResult trimFields(RelNode rel, BitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
   // We don't know how to trim this kind of relational expression, so give
   // it back intact.
   Util.discard(fieldsUsed);
   return new TrimResult(rel, Mappings.createIdentity(rel.getRowType().getFieldCount()));
 }
Пример #19
0
  /** 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);
  }