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113 lines
4.4 KiB
C++
113 lines
4.4 KiB
C++
#include <Storages/MergeTree/IMergeTreeReader.h>
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#include <Storages/MergeTree/MergeTreeReadPool.h>
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#include <Storages/MergeTree/MergeTreeThreadSelectBlockInputProcessor.h>
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#include <Interpreters/Context.h>
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namespace DB
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{
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MergeTreeThreadSelectBlockInputProcessor::MergeTreeThreadSelectBlockInputProcessor(
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const size_t thread_,
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const MergeTreeReadPoolPtr & pool_,
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const size_t min_marks_to_read_,
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const UInt64 max_block_size_rows_,
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size_t preferred_block_size_bytes_,
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size_t preferred_max_column_in_block_size_bytes_,
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const MergeTreeData & storage_,
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const StorageMetadataPtr & metadata_snapshot_,
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const bool use_uncompressed_cache_,
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const PrewhereInfoPtr & prewhere_info_,
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const MergeTreeReaderSettings & reader_settings_,
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const Names & virt_column_names_)
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:
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MergeTreeBaseSelectProcessor{
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pool_->getHeader(), storage_, metadata_snapshot_, prewhere_info_,
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max_block_size_rows_,
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preferred_block_size_bytes_, preferred_max_column_in_block_size_bytes_,
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reader_settings_, use_uncompressed_cache_, virt_column_names_},
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thread{thread_},
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pool{pool_}
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{
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/// round min_marks_to_read up to nearest multiple of block_size expressed in marks
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/// If granularity is adaptive it doesn't make sense
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/// Maybe it will make sense to add settings `max_block_size_bytes`
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if (max_block_size_rows && !storage.canUseAdaptiveGranularity())
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{
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size_t fixed_index_granularity = storage.getSettings()->index_granularity;
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min_marks_to_read = (min_marks_to_read_ * fixed_index_granularity + max_block_size_rows - 1)
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/ max_block_size_rows * max_block_size_rows / fixed_index_granularity;
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}
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else
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min_marks_to_read = min_marks_to_read_;
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ordered_names = getPort().getHeader().getNames();
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}
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/// Requests read task from MergeTreeReadPool and signals whether it got one
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bool MergeTreeThreadSelectBlockInputProcessor::getNewTask()
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{
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task = pool->getTask(min_marks_to_read, thread, ordered_names);
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if (!task)
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{
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/** Close the files (before destroying the object).
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* When many sources are created, but simultaneously reading only a few of them,
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* buffers don't waste memory.
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*/
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reader.reset();
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pre_reader.reset();
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return false;
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}
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const std::string part_name = task->data_part->name;
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/// Allows pool to reduce number of threads in case of too slow reads.
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auto profile_callback = [this](ReadBufferFromFileBase::ProfileInfo info_) { pool->profileFeedback(info_); };
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if (!reader)
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{
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auto rest_mark_ranges = pool->getRestMarks(*task->data_part, task->mark_ranges[0]);
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if (use_uncompressed_cache)
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owned_uncompressed_cache = storage.global_context.getUncompressedCache();
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owned_mark_cache = storage.global_context.getMarkCache();
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reader = task->data_part->getReader(task->columns, metadata_snapshot, rest_mark_ranges,
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owned_uncompressed_cache.get(), owned_mark_cache.get(), reader_settings,
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IMergeTreeReader::ValueSizeMap{}, profile_callback);
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if (prewhere_info)
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pre_reader = task->data_part->getReader(task->pre_columns, metadata_snapshot, rest_mark_ranges,
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owned_uncompressed_cache.get(), owned_mark_cache.get(), reader_settings,
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IMergeTreeReader::ValueSizeMap{}, profile_callback);
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}
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else
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{
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/// in other case we can reuse readers, anyway they will be "seeked" to required mark
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if (part_name != last_readed_part_name)
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{
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auto rest_mark_ranges = pool->getRestMarks(*task->data_part, task->mark_ranges[0]);
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/// retain avg_value_size_hints
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reader = task->data_part->getReader(task->columns, metadata_snapshot, rest_mark_ranges,
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owned_uncompressed_cache.get(), owned_mark_cache.get(), reader_settings,
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reader->getAvgValueSizeHints(), profile_callback);
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if (prewhere_info)
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pre_reader = task->data_part->getReader(task->pre_columns, metadata_snapshot, rest_mark_ranges,
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owned_uncompressed_cache.get(), owned_mark_cache.get(), reader_settings,
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reader->getAvgValueSizeHints(), profile_callback);
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}
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}
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last_readed_part_name = part_name;
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return true;
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}
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MergeTreeThreadSelectBlockInputProcessor::~MergeTreeThreadSelectBlockInputProcessor() = default;
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}
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