Ejemplo n.º 1
0
  /** 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);
  }
Ejemplo n.º 2
0
  public static void getSchemaObjectMonikers(
      SqlValidatorCatalogReader catalogReader, List<String> names, List<SqlMoniker> hints) {
    // Assume that the last name is 'dummy' or similar.
    List<String> subNames = Util.skipLast(names);
    hints.addAll(catalogReader.getAllSchemaObjectNames(subNames));

    // If the name has length 0, try prepending the name of the default
    // schema. So, the empty name would yield a list of tables in the
    // default schema, as well as a list of schemas from the above code.
    if (subNames.size() == 0) {
      hints.addAll(
          catalogReader.getAllSchemaObjectNames(
              Collections.singletonList(catalogReader.getSchemaName())));
    }
  }
Ejemplo n.º 3
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);
  }