#pragma once #include namespace DB { /// Used to read data from single part with select query in order of primary key. /// Cares about PREWHERE, virtual columns, indexes etc. /// To read data from multiple parts, Storage (MergeTree) creates multiple such objects. class MergeTreeInOrderSelectProcessor final : public MergeTreeSelectProcessor { public: template explicit MergeTreeInOrderSelectProcessor(Args &&... args) : MergeTreeSelectProcessor{std::forward(args)...} { LOG_TRACE(log, "Reading {} ranges in order from part {}, approx. {} rows starting from {}", all_mark_ranges.size(), data_part->name, total_rows, data_part->index_granularity.getMarkStartingRow(all_mark_ranges.front().begin)); } String getName() const override { return "MergeTreeInOrder"; } private: bool getNewTaskImpl() override; void finalizeNewTask() override {} Poco::Logger * log = &Poco::Logger::get("MergeTreeInOrderSelectProcessor"); }; }