Example #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);
   }
 }
Example #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);
   }
 }
Example #3
0
  /** 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);
  }
        public void onMatch(RelOptRuleCall call) {
          CalcRel calc = (CalcRel) call.getRels()[0];
          RexProgram program = calc.getProgram();
          final List<RexNode> exprList = program.getExprList();

          // Form a list of expressions with sub-expressions fully
          // expanded.
          final List<RexNode> expandedExprList = new ArrayList<RexNode>(exprList.size());
          final RexShuttle shuttle =
              new RexShuttle() {
                public RexNode visitLocalRef(RexLocalRef localRef) {
                  return expandedExprList.get(localRef.getIndex());
                }
              };
          for (RexNode expr : exprList) {
            expandedExprList.add(expr.accept(shuttle));
          }
          if (reduceExpressions(calc, expandedExprList)) {
            final RexProgramBuilder builder =
                new RexProgramBuilder(
                    calc.getChild().getRowType(), calc.getCluster().getRexBuilder());
            List<RexLocalRef> list = new ArrayList<RexLocalRef>();
            for (RexNode expr : expandedExprList) {
              list.add(builder.registerInput(expr));
            }
            if (program.getCondition() != null) {
              final int conditionIndex = program.getCondition().getIndex();
              final RexNode newConditionExp = expandedExprList.get(conditionIndex);
              if (newConditionExp.isAlwaysTrue()) {
                // condition is always TRUE - drop it
              } else if ((newConditionExp instanceof RexLiteral)
                  || RexUtil.isNullLiteral(newConditionExp, true)) {
                // condition is always NULL or FALSE - replace calc
                // with empty
                call.transformTo(new EmptyRel(calc.getCluster(), calc.getRowType()));
                return;
              } else {
                builder.addCondition(list.get(conditionIndex));
              }
            }
            int k = 0;
            for (RexLocalRef projectExpr : program.getProjectList()) {
              final int index = projectExpr.getIndex();
              builder.addProject(
                  list.get(index).getIndex(),
                  program.getOutputRowType().getFieldList().get(k++).getName());
            }
            call.transformTo(
                new CalcRel(
                    calc.getCluster(),
                    calc.getTraits(),
                    calc.getChild(),
                    calc.getRowType(),
                    builder.getProgram(),
                    calc.getCollationList()));

            // New plan is absolutely better than old plan.
            call.getPlanner().setImportance(calc, 0.0);
          }
        }
Example #5
0
 /**
  * Creates a ProjectRel with no sort keys.
  *
  * @param cluster Cluster this relational expression belongs to
  * @param child input relational expression
  * @param exps set of expressions for the input columns
  * @param fieldNames aliases of the expressions
  * @param flags values as in {@link ProjectRelBase.Flags}
  */
 public ProjectRel(
     RelOptCluster cluster, RelNode child, RexNode[] exps, String[] fieldNames, int flags) {
   this(
       cluster,
       child,
       exps,
       RexUtil.createStructType(cluster.getTypeFactory(), exps, fieldNames),
       flags,
       Collections.<RelCollation>emptyList());
 }
Example #6
0
 public ProjectRel clone() {
   ProjectRel clone =
       new ProjectRel(
           getCluster(),
           getChild().clone(),
           RexUtil.clone(exps),
           rowType,
           getFlags(),
           Collections.<RelCollation>emptyList());
   clone.inheritTraitsFrom(this);
   return clone;
 }
        public void onMatch(RelOptRuleCall call) {
          FilterRel filter = (FilterRel) call.rels[0];
          List<RexNode> expList = new ArrayList<RexNode>(Arrays.asList(filter.getChildExps()));
          RexNode newConditionExp;
          boolean reduced;
          if (reduceExpressions(filter, expList)) {
            assert (expList.size() == 1);
            newConditionExp = expList.get(0);
            reduced = true;
          } else {
            // No reduction, but let's still test the original
            // predicate to see if it was already a constant,
            // in which case we don't need any runtime decision
            // about filtering.
            newConditionExp = filter.getChildExps()[0];
            reduced = false;
          }
          if (newConditionExp.isAlwaysTrue()) {
            call.transformTo(filter.getChild());
          } else if ((newConditionExp instanceof RexLiteral)
              || RexUtil.isNullLiteral(newConditionExp, true)) {
            call.transformTo(new EmptyRel(filter.getCluster(), filter.getRowType()));
          } else if (reduced) {
            call.transformTo(CalcRel.createFilter(filter.getChild(), expList.get(0)));
          } else {
            if (newConditionExp instanceof RexCall) {
              RexCall rexCall = (RexCall) newConditionExp;
              boolean reverse = (rexCall.getOperator() == SqlStdOperatorTable.notOperator);
              if (reverse) {
                rexCall = (RexCall) rexCall.getOperands()[0];
              }
              reduceNotNullableFilter(call, filter, rexCall, reverse);
            }
            return;
          }

          // New plan is absolutely better than old plan.
          call.getPlanner().setImportance(filter, 0.0);
        }
Example #8
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);
  }