Method appendRecursiveExtend

src/planner/plan/append_extend.cpp:126–193

}

void Planner::appendRecursiveExtend(const std::shared_ptr<NodeExpression>& boundNode,
    const std::shared_ptr<NodeExpression>& nbrNode, const std::shared_ptr<RelExpression>& rel,
    ExtendDirection direction, LogicalPlan& plan) {
    // GDS pipeline
    auto recursiveInfo = rel->getRecursiveInfo();
    // Fill bind data with direction information. This can only be decided at planning time.
    auto bindData = recursiveInfo->bindData.get();
    bindData->nodeOutput = nbrNode;
    bindData->nodeInput = boundNode;
    bindData->extendDirection = direction;
    // If we extend from right to left, we need to print path in reverse direction.
    bindData->flipPath = *boundNode == *rel->getRightNode();
    auto resultColumns = recursiveInfo->function->getResultColumns(*bindData);
    auto recursiveExtend = std::make_shared<LogicalRecursiveExtend>(recursiveInfo->function->copy(),
        *recursiveInfo->bindData, resultColumns);
    if (recursiveInfo->nodePredicate != nullptr) {
        auto p = getNodeSemiMaskPlan(SemiMaskTargetType::RECURSIVE_EXTEND_PATH_NODE,
            *recursiveInfo->node, recursiveInfo->nodePredicate);
        recursiveExtend->addChild(p.getLastOperator());
    }
    recursiveExtend->computeFactorizedSchema();
    auto probePlan = LogicalPlan();
    probePlan.setLastOperator(std::move(recursiveExtend));
    // Scan path node property pipeline
    std::shared_ptr<LogicalOperator> pathNodePropertyScanRoot = nullptr;
    if (!recursiveInfo->nodeProjectionList.empty()) {
        auto pathNodePropertyScanPlan = LogicalPlan();
        createPathNodePropertyScanPlan(recursiveInfo->node, recursiveInfo->nodeProjectionList,
            pathNodePropertyScanPlan);
        pathNodePropertyScanRoot = pathNodePropertyScanPlan.getLastOperator();
    }
    // Scan path rel property pipeline
    std::shared_ptr<LogicalOperator> pathRelPropertyScanRoot = nullptr;
    if (!recursiveInfo->relProjectionList.empty()) {
        auto pathRelPropertyScanPlan = LogicalPlan();
        auto relProperties = recursiveInfo->relProjectionList;
        relProperties.push_back(recursiveInfo->rel->getInternalID());
        bool extendFromSource = *boundNode == *rel->getSrcNode();
        createPathRelPropertyScanPlan(recursiveInfo->node, recursiveInfo->nodeCopy,
            recursiveInfo->rel, direction, extendFromSource, relProperties,
            pathRelPropertyScanPlan);
        pathRelPropertyScanRoot = pathRelPropertyScanPlan.getLastOperator();
    }
    // Construct path by probing scanned properties
    auto pathPropertyProbe =
        std::make_shared<LogicalPathPropertyProbe>(rel, probePlan.getLastOperator(),
            pathNodePropertyScanRoot, pathRelPropertyScanRoot, RecursiveJoinType::TRACK_PATH);
    pathPropertyProbe->direction = direction;
    pathPropertyProbe->extendFromLeft = *boundNode == *rel->getLeftNode();
    pathPropertyProbe->pathNodeIDs = recursiveInfo->bindData->pathNodeIDsExpr;
    pathPropertyProbe->pathEdgeIDs = recursiveInfo->bindData->pathEdgeIDsExpr;
    pathPropertyProbe->computeFactorizedSchema();
    auto transaction = Transaction::Get(*clientContext);
    auto extensionRate =
        cardinalityEstimator.getExtensionRate(*rel, *boundNode, direction, transaction);
    auto resultCard =
        cardinalityEstimator.multiply(extensionRate, plan.getLastOperator()->getCardinality());
    pathPropertyProbe->setCardinality(resultCard);