Examples with Mapping org.apache.calcite.util.mapping.Mapping used on opensource projects

Example 6 with Mapping

use of org.apache.calcite.util.mapping.Mapping in project calcite by apache.

the class RelFieldTrimmer method dummyProject.

/**
 * Creates a project with a dummy column, to protect the parts of the system
 * that cannot handle a relational expression with no columns.
 *
 * @param fieldCount Number of fields in the original relational expression
 * @param input Trimmed input
 * @return Dummy project, or null if no dummy is required
 */
protected TrimResult dummyProject(int fieldCount, RelNode input) {
    final RelOptCluster cluster = input.getCluster();
    final Mapping mapping = Mappings.create(MappingType.INVERSE_SURJECTION, fieldCount, 1);
    if (input.getRowType().getFieldCount() == 1) {
        // created for the child). We can't do better.
        return result(input, mapping);
    }
    final RexLiteral expr = cluster.getRexBuilder().makeExactLiteral(BigDecimal.ZERO);
    relBuilder.push(input);
    relBuilder.project(ImmutableList.<RexNode>of(expr), ImmutableList.of("DUMMY"));
    return result(relBuilder.build(), mapping);
}

Example 7 with Mapping

use of org.apache.calcite.util.mapping.Mapping in project calcite by apache.

the class RelFieldTrimmer method trimFields.

/**
 * Variant of {@link #trimFields(RelNode, ImmutableBitSet, Set)} for
 * {@link org.apache.calcite.rel.logical.LogicalTableScan}.
 */
public TrimResult trimFields(final TableScan tableAccessRel, ImmutableBitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
    final int fieldCount = tableAccessRel.getRowType().getFieldCount();
    if (fieldsUsed.equals(ImmutableBitSet.range(fieldCount)) && extraFields.isEmpty()) {
        // then no need to introduce another RelNode
        return trimFields((RelNode) tableAccessRel, fieldsUsed, extraFields);
    }
    final RelNode newTableAccessRel = tableAccessRel.project(fieldsUsed, extraFields, relBuilder);
    // pretend that one field is used.
    if (fieldsUsed.cardinality() == 0) {
        RelNode input = newTableAccessRel;
        if (input instanceof Project) {
            // The table has implemented the project in the obvious way - by
            // creating project with 0 fields. Strip it away, and create our own
            // project with one field.
            Project project = (Project) input;
            if (project.getRowType().getFieldCount() == 0) {
                input = project.getInput();
            }
        }
        return dummyProject(fieldCount, input);
    }
    final Mapping mapping = createMapping(fieldsUsed, fieldCount);
    return result(newTableAccessRel, mapping);
}

Example 8 with Mapping

use of org.apache.calcite.util.mapping.Mapping in project calcite by apache.

the class RelFieldTrimmer method trimFields.

/**
 * Variant of {@link #trimFields(RelNode, ImmutableBitSet, Set)} for
 * {@link org.apache.calcite.rel.core.Sort}.
 */
public TrimResult trimFields(Sort sort, ImmutableBitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
    final RelDataType rowType = sort.getRowType();
    final int fieldCount = rowType.getFieldCount();
    final RelCollation collation = sort.getCollation();
    final RelNode input = sort.getInput();
    // We use the fields used by the consumer, plus any fields used as sort
    // keys.
    final ImmutableBitSet.Builder inputFieldsUsed = fieldsUsed.rebuild();
    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.build(), inputExtraFields);
    RelNode newInput = trimResult.left;
    final Mapping inputMapping = trimResult.right;
    // there's nothing we can do.
    if (newInput == input && inputMapping.isIdentity() && fieldsUsed.cardinality() == fieldCount) {
        return result(sort, Mappings.createIdentity(fieldCount));
    }
    // leave the Sort unchanged in case we have dynamic limits
    if (sort.offset instanceof RexDynamicParam || sort.fetch instanceof RexDynamicParam) {
        return result(sort, inputMapping);
    }
    relBuilder.push(newInput);
    final int offset = sort.offset == null ? 0 : RexLiteral.intValue(sort.offset);
    final int fetch = sort.fetch == null ? -1 : RexLiteral.intValue(sort.fetch);
    final ImmutableList<RexNode> fields = relBuilder.fields(RexUtil.apply(inputMapping, collation));
    relBuilder.sortLimit(offset, fetch, fields);
    // needs them for its condition.
    return result(relBuilder.build(), inputMapping);
}

Example 9 with Mapping

use of org.apache.calcite.util.mapping.Mapping in project hive by apache.

the class RelFieldTrimmer method trimFields.

/**
 * Variant of {@link #trimFields(RelNode, ImmutableBitSet, Set)} for
 * {@link org.apache.calcite.rel.logical.LogicalAggregate}.
 */
public TrimResult trimFields(Aggregate aggregate, ImmutableBitSet fieldsUsed, Set<RelDataTypeField> extraFields) {
    // Fields:
    // 
    // | sys fields | group fields | indicator 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 group and indicator fields stay, even if they are not used.
    final RelDataType rowType = aggregate.getRowType();
    // Compute which input fields are used.
    // 1. group fields are always used
    final ImmutableBitSet.Builder inputFieldsUsed = aggregate.getGroupSet().rebuild();
    // 2. agg functions
    for (AggregateCall aggCall : aggregate.getAggCallList()) {
        inputFieldsUsed.addAll(aggCall.getArgList());
        if (aggCall.filterArg >= 0) {
            inputFieldsUsed.set(aggCall.filterArg);
        }
        inputFieldsUsed.addAll(RelCollations.ordinals(aggCall.collation));
    }
    // Create input with trimmed columns.
    final RelNode input = aggregate.getInput();
    final Set<RelDataTypeField> inputExtraFields = Collections.emptySet();
    final TrimResult trimResult = trimChild(aggregate, input, inputFieldsUsed.build(), inputExtraFields);
    final RelNode newInput = trimResult.left;
    final Mapping inputMapping = trimResult.right;
    // We have to return group keys and (if present) indicators.
    // So, pretend that the consumer asked for them.
    final int groupCount = aggregate.getGroupSet().cardinality();
    fieldsUsed = fieldsUsed.union(ImmutableBitSet.range(groupCount));
    // there's nothing to do.
    if (input == newInput && fieldsUsed.equals(ImmutableBitSet.range(rowType.getFieldCount()))) {
        return result(aggregate, Mappings.createIdentity(rowType.getFieldCount()));
    }
    // Which agg calls are used by our consumer?
    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.INVERSE_SURJECTION, rowType.getFieldCount(), groupCount + usedAggCallCount);
    final ImmutableBitSet newGroupSet = Mappings.apply(inputMapping, aggregate.getGroupSet());
    final ImmutableList<ImmutableBitSet> newGroupSets = ImmutableList.copyOf(Iterables.transform(aggregate.getGroupSets(), input1 -> Mappings.apply(inputMapping, input1)));
    // indicator fields first.
    for (j = 0; j < groupCount; j++) {
        mapping.set(j, j);
    }
    // Now create new agg calls, and populate mapping for them.
    final RelBuilder relBuilder = REL_BUILDER.get();
    relBuilder.push(newInput);
    final List<RelBuilder.AggCall> newAggCallList = new ArrayList<>();
    j = groupCount;
    for (AggregateCall aggCall : aggregate.getAggCallList()) {
        if (fieldsUsed.get(j)) {
            final ImmutableList<RexNode> args = relBuilder.fields(Mappings.apply2(inputMapping, aggCall.getArgList()));
            final RexNode filterArg = aggCall.filterArg < 0 ? null : relBuilder.field(Mappings.apply(inputMapping, aggCall.filterArg));
            RelBuilder.AggCall newAggCall = relBuilder.aggregateCall(aggCall.getAggregation(), args).distinct(aggCall.isDistinct()).filter(filterArg).approximate(aggCall.isApproximate()).sort(relBuilder.fields(aggCall.collation)).as(aggCall.name);
            mapping.set(j, groupCount + newAggCallList.size());
            newAggCallList.add(newAggCall);
        }
        ++j;
    }
    final RelBuilder.GroupKey groupKey = relBuilder.groupKey(newGroupSet, newGroupSets);
    relBuilder.aggregate(groupKey, newAggCallList);
    return result(relBuilder.build(), mapping);
}

Example 10 with Mapping

use of org.apache.calcite.util.mapping.Mapping in project hive by apache.

the class RelFieldTrimmer method dispatchTrimFields.

/**
 * 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, ImmutableBitSet 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 || Bug.TODO_FIXED : "target: " + mapping.getTargetCount() + " + " + extraFields.size() + " != " + newFieldCount;
    if (Bug.TODO_FIXED) {
        assert newFieldCount > 0 : "rel has no fields after trim: " + rel;
    }
    if (newRel.equals(rel)) {
        return result(rel, mapping);
    }
    return trimResult;
}