Examples with VariableReferenceExpression com.facebook.presto.spi.relation.VariableReferenceExpression used on opensource projects

Example 66 with VariableReferenceExpression

use of com.facebook.presto.spi.relation.VariableReferenceExpression in project presto by prestodb.

the class QueryPlanner method handleGroupingOperations.

private PlanBuilder handleGroupingOperations(PlanBuilder subPlan, QuerySpecification node, Optional<VariableReferenceExpression> groupIdVariable, List<Set<FieldId>> groupingSets) {
    if (analysis.getGroupingOperations(node).isEmpty()) {
        return subPlan;
    }
    TranslationMap newTranslations = subPlan.copyTranslations();
    Assignments.Builder projections = Assignments.builder();
    projections.putAll(identitiesAsSymbolReferences(subPlan.getRoot().getOutputVariables()));
    List<Set<Integer>> descriptor = groupingSets.stream().map(set -> set.stream().map(FieldId::getFieldIndex).collect(toImmutableSet())).collect(toImmutableList());
    for (GroupingOperation groupingOperation : analysis.getGroupingOperations(node)) {
        Expression rewritten = GroupingOperationRewriter.rewriteGroupingOperation(groupingOperation, descriptor, analysis.getColumnReferenceFields(), groupIdVariable);
        Type coercion = analysis.getCoercion(groupingOperation);
        VariableReferenceExpression variable = variableAllocator.newVariable(rewritten, analysis.getTypeWithCoercions(groupingOperation));
        if (coercion != null) {
            rewritten = new Cast(rewritten, coercion.getTypeSignature().toString(), false, metadata.getFunctionAndTypeManager().isTypeOnlyCoercion(analysis.getType(groupingOperation), coercion));
        }
        projections.put(variable, castToRowExpression(rewritten));
        newTranslations.put(groupingOperation, variable);
    }
    return new PlanBuilder(newTranslations, new ProjectNode(subPlan.getRoot().getSourceLocation(), idAllocator.getNextId(), subPlan.getRoot(), projections.build(), LOCAL));
}

Example 67 with VariableReferenceExpression

use of com.facebook.presto.spi.relation.VariableReferenceExpression in project presto by prestodb.

the class QueryPlanner method aggregate.

private PlanBuilder aggregate(PlanBuilder subPlan, QuerySpecification node) {
    if (!analysis.isAggregation(node)) {
        return subPlan;
    }
    // 1. Pre-project all scalar inputs (arguments and non-trivial group by expressions)
    Set<Expression> groupByExpressions = ImmutableSet.copyOf(analysis.getGroupByExpressions(node));
    ImmutableList.Builder<Expression> arguments = ImmutableList.builder();
    analysis.getAggregates(node).stream().map(FunctionCall::getArguments).flatMap(List::stream).filter(// lambda expression is generated at execution time
    exp -> !(exp instanceof LambdaExpression)).forEach(arguments::add);
    analysis.getAggregates(node).stream().map(FunctionCall::getOrderBy).filter(Optional::isPresent).map(Optional::get).map(OrderBy::getSortItems).flatMap(List::stream).map(SortItem::getSortKey).forEach(arguments::add);
    // filter expressions need to be projected first
    analysis.getAggregates(node).stream().map(FunctionCall::getFilter).filter(Optional::isPresent).map(Optional::get).forEach(arguments::add);
    Iterable<Expression> inputs = Iterables.concat(groupByExpressions, arguments.build());
    subPlan = handleSubqueries(subPlan, node, inputs);
    if (!Iterables.isEmpty(inputs)) {
        // avoid an empty projection if the only aggregation is COUNT (which has no arguments)
        subPlan = project(subPlan, inputs);
    }
    // 2. Aggregate
    // 2.a. Rewrite aggregate arguments
    TranslationMap argumentTranslations = new TranslationMap(subPlan.getRelationPlan(), analysis, lambdaDeclarationToVariableMap);
    ImmutableList.Builder<VariableReferenceExpression> aggregationArgumentsBuilder = ImmutableList.builder();
    for (Expression argument : arguments.build()) {
        VariableReferenceExpression variable = subPlan.translate(argument);
        argumentTranslations.put(argument, variable);
        aggregationArgumentsBuilder.add(variable);
    }
    List<VariableReferenceExpression> aggregationArguments = aggregationArgumentsBuilder.build();
    // 2.b. Rewrite grouping columns
    TranslationMap groupingTranslations = new TranslationMap(subPlan.getRelationPlan(), analysis, lambdaDeclarationToVariableMap);
    Map<VariableReferenceExpression, VariableReferenceExpression> groupingSetMappings = new LinkedHashMap<>();
    for (Expression expression : groupByExpressions) {
        VariableReferenceExpression input = subPlan.translate(expression);
        VariableReferenceExpression output = variableAllocator.newVariable(expression, analysis.getTypeWithCoercions(expression), "gid");
        groupingTranslations.put(expression, output);
        groupingSetMappings.put(output, input);
    }
    // This tracks the grouping sets before complex expressions are considered (see comments below)
    // It's also used to compute the descriptors needed to implement grouping()
    List<Set<FieldId>> columnOnlyGroupingSets = ImmutableList.of(ImmutableSet.of());
    List<List<VariableReferenceExpression>> groupingSets = ImmutableList.of(ImmutableList.of());
    if (node.getGroupBy().isPresent()) {
        // For the purpose of "distinct", we need to canonicalize column references that may have varying
        // syntactic forms (e.g., "t.a" vs "a"). Thus we need to enumerate grouping sets based on the underlying
        // fieldId associated with each column reference expression.
        // The catch is that simple group-by expressions can be arbitrary expressions (this is a departure from the SQL specification).
        // But, they don't affect the number of grouping sets or the behavior of "distinct" . We can compute all the candidate
        // grouping sets in terms of fieldId, dedup as appropriate and then cross-join them with the complex expressions.
        Analysis.GroupingSetAnalysis groupingSetAnalysis = analysis.getGroupingSets(node);
        columnOnlyGroupingSets = enumerateGroupingSets(groupingSetAnalysis);
        if (node.getGroupBy().get().isDistinct()) {
            columnOnlyGroupingSets = columnOnlyGroupingSets.stream().distinct().collect(toImmutableList());
        }
        // add in the complex expressions an turn materialize the grouping sets in terms of plan columns
        ImmutableList.Builder<List<VariableReferenceExpression>> groupingSetBuilder = ImmutableList.builder();
        for (Set<FieldId> groupingSet : columnOnlyGroupingSets) {
            ImmutableList.Builder<VariableReferenceExpression> columns = ImmutableList.builder();
            groupingSetAnalysis.getComplexExpressions().stream().map(groupingTranslations::get).forEach(columns::add);
            groupingSet.stream().map(field -> groupingTranslations.get(new FieldReference(field.getFieldIndex()))).forEach(columns::add);
            groupingSetBuilder.add(columns.build());
        }
        groupingSets = groupingSetBuilder.build();
    }
    // 2.c. Generate GroupIdNode (multiple grouping sets) or ProjectNode (single grouping set)
    Optional<VariableReferenceExpression> groupIdVariable = Optional.empty();
    if (groupingSets.size() > 1) {
        groupIdVariable = Optional.of(variableAllocator.newVariable("groupId", BIGINT));
        GroupIdNode groupId = new GroupIdNode(subPlan.getRoot().getSourceLocation(), idAllocator.getNextId(), subPlan.getRoot(), groupingSets, groupingSetMappings, aggregationArguments, groupIdVariable.get());
        subPlan = new PlanBuilder(groupingTranslations, groupId);
    } else {
        Assignments.Builder assignments = Assignments.builder();
        aggregationArguments.stream().map(AssignmentUtils::identityAsSymbolReference).forEach(assignments::put);
        groupingSetMappings.forEach((key, value) -> assignments.put(key, castToRowExpression(asSymbolReference(value))));
        ProjectNode project = new ProjectNode(subPlan.getRoot().getSourceLocation(), idAllocator.getNextId(), subPlan.getRoot(), assignments.build(), LOCAL);
        subPlan = new PlanBuilder(groupingTranslations, project);
    }
    TranslationMap aggregationTranslations = new TranslationMap(subPlan.getRelationPlan(), analysis, lambdaDeclarationToVariableMap);
    aggregationTranslations.copyMappingsFrom(groupingTranslations);
    // 2.d. Rewrite aggregates
    ImmutableMap.Builder<VariableReferenceExpression, Aggregation> aggregationsBuilder = ImmutableMap.builder();
    boolean needPostProjectionCoercion = false;
    for (FunctionCall aggregate : analysis.getAggregates(node)) {
        Expression rewritten = argumentTranslations.rewrite(aggregate);
        VariableReferenceExpression newVariable = variableAllocator.newVariable(rewritten, analysis.getType(aggregate));
        // Therefore we can end up with this implicit cast, and have to move it into a post-projection
        if (rewritten instanceof Cast) {
            rewritten = ((Cast) rewritten).getExpression();
            needPostProjectionCoercion = true;
        }
        aggregationTranslations.put(aggregate, newVariable);
        FunctionCall rewrittenFunction = (FunctionCall) rewritten;
        aggregationsBuilder.put(newVariable, new Aggregation(new CallExpression(getSourceLocation(rewrittenFunction), aggregate.getName().getSuffix(), analysis.getFunctionHandle(aggregate), analysis.getType(aggregate), rewrittenFunction.getArguments().stream().map(OriginalExpressionUtils::castToRowExpression).collect(toImmutableList())), rewrittenFunction.getFilter().map(OriginalExpressionUtils::castToRowExpression), rewrittenFunction.getOrderBy().map(orderBy -> toOrderingScheme(orderBy, variableAllocator.getTypes())), rewrittenFunction.isDistinct(), Optional.empty()));
    }
    Map<VariableReferenceExpression, Aggregation> aggregations = aggregationsBuilder.build();
    ImmutableSet.Builder<Integer> globalGroupingSets = ImmutableSet.builder();
    for (int i = 0; i < groupingSets.size(); i++) {
        if (groupingSets.get(i).isEmpty()) {
            globalGroupingSets.add(i);
        }
    }
    ImmutableList.Builder<VariableReferenceExpression> groupingKeys = ImmutableList.builder();
    groupingSets.stream().flatMap(List::stream).distinct().forEach(groupingKeys::add);
    groupIdVariable.ifPresent(groupingKeys::add);
    AggregationNode aggregationNode = new AggregationNode(subPlan.getRoot().getSourceLocation(), idAllocator.getNextId(), subPlan.getRoot(), aggregations, groupingSets(groupingKeys.build(), groupingSets.size(), globalGroupingSets.build()), ImmutableList.of(), AggregationNode.Step.SINGLE, Optional.empty(), groupIdVariable);
    subPlan = new PlanBuilder(aggregationTranslations, aggregationNode);
    // TODO: this is a hack, we should change type coercions to coerce the inputs to functions/operators instead of coercing the output
    if (needPostProjectionCoercion) {
        ImmutableList.Builder<Expression> alreadyCoerced = ImmutableList.builder();
        alreadyCoerced.addAll(groupByExpressions);
        groupIdVariable.map(ExpressionTreeUtils::createSymbolReference).ifPresent(alreadyCoerced::add);
        subPlan = explicitCoercionFields(subPlan, alreadyCoerced.build(), analysis.getAggregates(node));
    }
    // 4. Project and re-write all grouping functions
    return handleGroupingOperations(subPlan, node, groupIdVariable, columnOnlyGroupingSets);
}

Example 68 with VariableReferenceExpression

use of com.facebook.presto.spi.relation.VariableReferenceExpression in project presto by prestodb.

the class RelationPlanner method visitValues.

@Override
protected RelationPlan visitValues(Values node, Void context) {
    Scope scope = analysis.getScope(node);
    ImmutableList.Builder<VariableReferenceExpression> outputVariablesBuilder = ImmutableList.builder();
    for (Field field : scope.getRelationType().getVisibleFields()) {
        outputVariablesBuilder.add(variableAllocator.newVariable(field));
    }
    ImmutableList.Builder<List<RowExpression>> rowsBuilder = ImmutableList.builder();
    for (Expression row : node.getRows()) {
        ImmutableList.Builder<RowExpression> values = ImmutableList.builder();
        if (row instanceof Row) {
            for (Expression item : ((Row) row).getItems()) {
                values.add(rewriteRow(item));
            }
        } else {
            values.add(rewriteRow(row));
        }
        rowsBuilder.add(values.build());
    }
    ValuesNode valuesNode = new ValuesNode(getSourceLocation(node), idAllocator.getNextId(), outputVariablesBuilder.build(), rowsBuilder.build());
    return new RelationPlan(valuesNode, scope, outputVariablesBuilder.build());
}

Example 69 with VariableReferenceExpression

use of com.facebook.presto.spi.relation.VariableReferenceExpression in project presto by prestodb.

the class RelationPlanner method visitAliasedRelation.

@Override
protected RelationPlan visitAliasedRelation(AliasedRelation node, Void context) {
    RelationPlan subPlan = process(node.getRelation(), context);
    PlanNode root = subPlan.getRoot();
    List<VariableReferenceExpression> mappings = subPlan.getFieldMappings();
    if (node.getColumnNames() != null) {
        ImmutableList.Builder<VariableReferenceExpression> newMappings = ImmutableList.builder();
        Assignments.Builder assignments = Assignments.builder();
        // project only the visible columns from the underlying relation
        for (int i = 0; i < subPlan.getDescriptor().getAllFieldCount(); i++) {
            Field field = subPlan.getDescriptor().getFieldByIndex(i);
            if (!field.isHidden()) {
                VariableReferenceExpression aliasedColumn = variableAllocator.newVariable(mappings.get(i).getSourceLocation(), field);
                assignments.put(aliasedColumn, castToRowExpression(asSymbolReference(subPlan.getFieldMappings().get(i))));
                newMappings.add(aliasedColumn);
            }
        }
        root = new ProjectNode(getSourceLocation(node.getLocation()), idAllocator.getNextId(), subPlan.getRoot(), assignments.build(), LOCAL);
        mappings = newMappings.build();
    }
    return new RelationPlan(root, analysis.getScope(node), mappings);
}

Example 70 with VariableReferenceExpression

use of com.facebook.presto.spi.relation.VariableReferenceExpression in project presto by prestodb.

the class RelationPlanner method planCrossJoinUnnest.

private RelationPlan planCrossJoinUnnest(RelationPlan leftPlan, Join joinNode, Unnest node) {
    RelationType unnestOutputDescriptor = analysis.getOutputDescriptor(node);
    // Create variables for the result of unnesting
    ImmutableList.Builder<VariableReferenceExpression> unnestedVariablesBuilder = ImmutableList.builder();
    for (Field field : unnestOutputDescriptor.getVisibleFields()) {
        VariableReferenceExpression variable = variableAllocator.newVariable(field);
        unnestedVariablesBuilder.add(variable);
    }
    ImmutableList<VariableReferenceExpression> unnestedVariables = unnestedVariablesBuilder.build();
    // Add a projection for all the unnest arguments
    PlanBuilder planBuilder = initializePlanBuilder(leftPlan);
    planBuilder = planBuilder.appendProjections(node.getExpressions(), variableAllocator, idAllocator);
    TranslationMap translations = planBuilder.getTranslations();
    ProjectNode projectNode = (ProjectNode) planBuilder.getRoot();
    ImmutableMap.Builder<VariableReferenceExpression, List<VariableReferenceExpression>> unnestVariables = ImmutableMap.builder();
    UnmodifiableIterator<VariableReferenceExpression> unnestedVariablesIterator = unnestedVariables.iterator();
    for (Expression expression : node.getExpressions()) {
        Type type = analysis.getType(expression);
        VariableReferenceExpression inputVariable = new VariableReferenceExpression(getSourceLocation(expression), translations.get(expression).getName(), type);
        if (type instanceof ArrayType) {
            Type elementType = ((ArrayType) type).getElementType();
            if (!SystemSessionProperties.isLegacyUnnest(session) && elementType instanceof RowType) {
                ImmutableList.Builder<VariableReferenceExpression> unnestVariableBuilder = ImmutableList.builder();
                for (int i = 0; i < ((RowType) elementType).getFields().size(); i++) {
                    unnestVariableBuilder.add(unnestedVariablesIterator.next());
                }
                unnestVariables.put(inputVariable, unnestVariableBuilder.build());
            } else {
                unnestVariables.put(inputVariable, ImmutableList.of(unnestedVariablesIterator.next()));
            }
        } else if (type instanceof MapType) {
            unnestVariables.put(inputVariable, ImmutableList.of(unnestedVariablesIterator.next(), unnestedVariablesIterator.next()));
        } else {
            throw new IllegalArgumentException("Unsupported type for UNNEST: " + type);
        }
    }
    Optional<VariableReferenceExpression> ordinalityVariable = node.isWithOrdinality() ? Optional.of(unnestedVariablesIterator.next()) : Optional.empty();
    checkState(!unnestedVariablesIterator.hasNext(), "Not all output variables were matched with input variables");
    UnnestNode unnestNode = new UnnestNode(getSourceLocation(node), idAllocator.getNextId(), projectNode, leftPlan.getFieldMappings(), unnestVariables.build(), ordinalityVariable);
    return new RelationPlan(unnestNode, analysis.getScope(joinNode), unnestNode.getOutputVariables());
}