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125 lines
3.2 KiB
C++
125 lines
3.2 KiB
C++
#include <Storages/MergeTree/MergeTreeReverseSelectProcessor.h>
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#include <Storages/MergeTree/IntersectionsIndexes.h>
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#include "Storages/MergeTree/MergeTreeBaseSelectProcessor.h"
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namespace DB
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{
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namespace ErrorCodes
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{
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extern const int MEMORY_LIMIT_EXCEEDED;
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}
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bool MergeTreeReverseSelectAlgorithm::getNewTaskImpl()
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try
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{
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if (pool)
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return getNewTaskParallelReplicas();
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else
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return getNewTaskOrdinaryReading();
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}
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catch (...)
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{
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/// Suspicion of the broken part. A part is added to the queue for verification.
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if (getCurrentExceptionCode() != ErrorCodes::MEMORY_LIMIT_EXCEEDED)
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storage.reportBrokenPart(data_part);
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throw;
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}
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bool MergeTreeReverseSelectAlgorithm::getNewTaskOrdinaryReading()
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{
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if (chunks.empty() && all_mark_ranges.empty())
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return false;
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/// We have some blocks to return in buffer.
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/// Return true to continue reading, but actually don't create a task.
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if (all_mark_ranges.empty())
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return true;
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if (!reader)
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initializeReaders();
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/// Read ranges from right to left.
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MarkRanges mark_ranges_for_task{std::move(all_mark_ranges.back())};
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all_mark_ranges.pop_back();
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auto size_predictor = (preferred_block_size_bytes == 0) ? nullptr
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: getSizePredictor(data_part, task_columns, sample_block);
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task = std::make_unique<MergeTreeReadTask>(
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data_part, mark_ranges_for_task, part_index_in_query, column_name_set,
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task_columns, std::move(size_predictor));
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return true;
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}
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bool MergeTreeReverseSelectAlgorithm::getNewTaskParallelReplicas()
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{
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if (chunks.empty() && no_more_tasks)
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return false;
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/// We have some blocks to return in buffer.
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/// Return true to continue reading, but actually don't create a task.
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if (no_more_tasks)
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return true;
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if (!reader)
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initializeReaders();
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auto description = RangesInDataPartDescription{
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.info = data_part->info,
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/// We just ignore all the distribution done before
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/// Everything will be done on coordinator side
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.ranges = {},
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};
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auto mark_ranges_for_task = pool->getNewTask(description);
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if (mark_ranges_for_task.empty())
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{
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/// If we have chunks in buffer - return true to continue reading from them
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return !chunks.empty();
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}
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auto size_predictor = (preferred_block_size_bytes == 0) ? nullptr
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: getSizePredictor(data_part, task_columns, sample_block);
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task = std::make_unique<MergeTreeReadTask>(
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data_part, mark_ranges_for_task, part_index_in_query, column_name_set,
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task_columns, std::move(size_predictor));
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return true;
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}
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MergeTreeReverseSelectAlgorithm::BlockAndProgress MergeTreeReverseSelectAlgorithm::readFromPart()
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{
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BlockAndProgress res;
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if (!chunks.empty())
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{
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res = std::move(chunks.back());
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chunks.pop_back();
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return res;
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}
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if (!task->range_reader.isInitialized())
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initializeRangeReaders(*task);
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while (!task->isFinished())
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{
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auto chunk = readFromPartImpl();
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chunks.push_back(std::move(chunk));
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}
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if (chunks.empty())
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return {};
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res = std::move(chunks.back());
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chunks.pop_back();
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return res;
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}
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}
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