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ed5b521110
* Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2]. * Less dependencies [#CLICKHOUSE-2].
620 lines
22 KiB
C++
620 lines
22 KiB
C++
#include <DB/DataTypes/IDataType.h>
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#include <DB/DataTypes/DataTypeNested.h>
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#include <DB/DataTypes/DataTypeArray.h>
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#include <DB/DataTypes/DataTypeNullable.h>
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#include <DB/Common/escapeForFileName.h>
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#include <DB/IO/CachedCompressedReadBuffer.h>
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#include <DB/IO/CompressedReadBufferFromFile.h>
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#include <DB/Columns/ColumnArray.h>
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#include <DB/Interpreters/evaluateMissingDefaults.h>
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#include <DB/Storages/MergeTree/MergeTreeReader.h>
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#include <DB/Columns/ColumnNullable.h>
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#include <Poco/File.h>
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namespace DB
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{
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namespace
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{
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using OffsetColumns = std::map<std::string, ColumnPtr>;
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constexpr auto DATA_FILE_EXTENSION = ".bin";
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constexpr auto NULL_MAP_EXTENSION = ".null.bin";
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bool isNullStream(const std::string & extension)
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{
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return extension == NULL_MAP_EXTENSION;
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}
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}
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namespace ErrorCodes
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{
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extern const int NOT_FOUND_EXPECTED_DATA_PART;
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extern const int MEMORY_LIMIT_EXCEEDED;
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}
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MergeTreeReader::~MergeTreeReader() = default;
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MergeTreeReader::MergeTreeReader(const String & path, /// Путь к куску
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const MergeTreeData::DataPartPtr & data_part, const NamesAndTypesList & columns,
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UncompressedCache * uncompressed_cache, MarkCache * mark_cache, bool save_marks_in_cache,
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MergeTreeData & storage, const MarkRanges & all_mark_ranges,
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size_t aio_threshold, size_t max_read_buffer_size, const ValueSizeMap & avg_value_size_hints,
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const ReadBufferFromFileBase::ProfileCallback & profile_callback,
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clockid_t clock_type)
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: avg_value_size_hints(avg_value_size_hints), path(path), data_part(data_part), columns(columns),
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uncompressed_cache(uncompressed_cache), mark_cache(mark_cache), save_marks_in_cache(save_marks_in_cache), storage(storage),
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all_mark_ranges(all_mark_ranges), aio_threshold(aio_threshold), max_read_buffer_size(max_read_buffer_size)
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{
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try
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{
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if (!Poco::File(path).exists())
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throw Exception("Part " + path + " is missing", ErrorCodes::NOT_FOUND_EXPECTED_DATA_PART);
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for (const NameAndTypePair & column : columns)
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addStream(column.name, *column.type, all_mark_ranges, profile_callback, clock_type);
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}
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catch (...)
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{
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storage.reportBrokenPart(data_part->name);
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throw;
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}
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}
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const MergeTreeReader::ValueSizeMap & MergeTreeReader::getAvgValueSizeHints() const
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{
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return avg_value_size_hints;
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}
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void MergeTreeReader::readRange(size_t from_mark, size_t to_mark, Block & res)
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{
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try
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{
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size_t max_rows_to_read = (to_mark - from_mark) * storage.index_granularity;
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/// Указатели на столбцы смещений, общие для столбцов из вложенных структур данных
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/// Если append, все значения nullptr, и offset_columns используется только для проверки, что столбец смещений уже прочитан.
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OffsetColumns offset_columns;
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for (const NameAndTypePair & it : columns)
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{
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if (streams.end() == streams.find(it.name))
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continue;
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/// Все столбцы уже есть в блоке. Будем добавлять значения в конец.
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bool append = res.has(it.name);
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ColumnWithTypeAndName column;
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column.name = it.name;
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column.type = it.type;
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if (append)
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column.column = res.getByName(column.name).column;
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bool read_offsets = true;
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const IDataType * observed_type;
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bool is_nullable;
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if (column.type.get()->isNullable())
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{
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const DataTypeNullable & nullable_type = static_cast<const DataTypeNullable &>(*column.type);
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observed_type = nullable_type.getNestedType().get();
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is_nullable = true;
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}
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else
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{
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observed_type = column.type.get();
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is_nullable = false;
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}
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/// Для вложенных структур запоминаем указатели на столбцы со смещениями
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if (const DataTypeArray * type_arr = typeid_cast<const DataTypeArray *>(observed_type))
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{
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String name = DataTypeNested::extractNestedTableName(column.name);
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if (offset_columns.count(name) == 0)
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offset_columns[name] = append ? nullptr : std::make_shared<ColumnArray::ColumnOffsets_t>();
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else
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read_offsets = false; /// на предыдущих итерациях смещения уже считали вызовом readData
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if (!append)
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{
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column.column = std::make_shared<ColumnArray>(type_arr->getNestedType()->createColumn(), offset_columns[name]);
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if (is_nullable)
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column.column = std::make_shared<ColumnNullable>(column.column, std::make_shared<ColumnUInt8>());
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}
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}
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else if (!append)
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column.column = column.type->createColumn();
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try
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{
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readData(column.name, *column.type, *column.column, from_mark, max_rows_to_read, 0, read_offsets);
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}
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catch (Exception & e)
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{
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/// Более хорошая диагностика.
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e.addMessage("(while reading column " + column.name + ")");
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throw;
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}
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if (!append && column.column->size())
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res.insert(std::move(column));
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}
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}
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catch (Exception & e)
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{
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if (e.code() != ErrorCodes::MEMORY_LIMIT_EXCEEDED)
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storage.reportBrokenPart(data_part->name);
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/// Более хорошая диагностика.
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e.addMessage("(while reading from part " + path + " from mark " + toString(from_mark) + " to " + toString(to_mark) + ")");
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throw;
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}
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catch (...)
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{
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storage.reportBrokenPart(data_part->name);
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throw;
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}
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}
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void MergeTreeReader::fillMissingColumns(Block & res, const Names & ordered_names, const bool always_reorder)
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{
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fillMissingColumnsImpl(res, ordered_names, always_reorder);
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}
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void MergeTreeReader::fillMissingColumnsAndReorder(Block & res, const Names & ordered_names)
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{
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fillMissingColumnsImpl(res, ordered_names, true);
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}
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MergeTreeReader::Stream::Stream(
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const String & path_prefix_, const String & extension_,
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UncompressedCache * uncompressed_cache,
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MarkCache * mark_cache, bool save_marks_in_cache,
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const MarkRanges & all_mark_ranges, size_t aio_threshold, size_t max_read_buffer_size,
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const ReadBufferFromFileBase::ProfileCallback & profile_callback, clockid_t clock_type)
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: path_prefix(path_prefix_), extension(extension_)
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{
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loadMarks(mark_cache, save_marks_in_cache, isNullStream(extension));
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/// Compute the size of the buffer.
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size_t max_mark_range = 0;
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for (size_t i = 0; i < all_mark_ranges.size(); ++i)
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{
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size_t right = all_mark_ranges[i].end;
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/// Если правая граница лежит внутри блока, то его тоже придется читать.
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if (right < (*marks).size() && (*marks)[right].offset_in_decompressed_block > 0)
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{
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while (right < (*marks).size()
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&& (*marks)[right].offset_in_compressed_file
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== (*marks)[all_mark_ranges[i].end].offset_in_compressed_file)
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{
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++right;
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}
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}
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/// Если правее засечек нет, просто используем max_read_buffer_size
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if (right >= (*marks).size()
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|| (right + 1 == (*marks).size()
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&& (*marks)[right].offset_in_compressed_file
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== (*marks)[all_mark_ranges[i].end].offset_in_compressed_file))
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{
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max_mark_range = max_read_buffer_size;
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break;
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}
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max_mark_range = std::max(max_mark_range,
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(*marks)[right].offset_in_compressed_file - (*marks)[all_mark_ranges[i].begin].offset_in_compressed_file);
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}
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size_t buffer_size = std::min(max_read_buffer_size, max_mark_range);
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/// Compute the estimated size of the data to be read.
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size_t estimated_size = 0;
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if (aio_threshold > 0)
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{
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for (const auto & mark_range : all_mark_ranges)
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{
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size_t offset_begin = (*marks)[mark_range.begin].offset_in_compressed_file;
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size_t offset_end;
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if (mark_range.end < (*marks).size())
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offset_end = (*marks)[mark_range.end].offset_in_compressed_file;
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else
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offset_end = Poco::File(path_prefix + extension).getSize();
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if (offset_end > 0)
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estimated_size += offset_end - offset_begin;
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}
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}
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/// Initialize the objects that shall be used to perform read operations.
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if (uncompressed_cache)
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{
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auto buffer = std::make_unique<CachedCompressedReadBuffer>(
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path_prefix + extension, uncompressed_cache, estimated_size, aio_threshold, buffer_size);
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if (profile_callback)
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buffer->setProfileCallback(profile_callback, clock_type);
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cached_buffer = std::move(buffer);
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data_buffer = cached_buffer.get();
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}
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else
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{
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auto buffer = std::make_unique<CompressedReadBufferFromFile>(
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path_prefix + extension, estimated_size, aio_threshold, buffer_size);
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if (profile_callback)
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buffer->setProfileCallback(profile_callback, clock_type);
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non_cached_buffer = std::move(buffer);
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data_buffer = non_cached_buffer.get();
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}
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}
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std::unique_ptr<MergeTreeReader::Stream> MergeTreeReader::Stream::createEmptyPtr()
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{
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std::unique_ptr<Stream> res(new Stream);
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res->is_empty = true;
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return res;
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}
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void MergeTreeReader::Stream::loadMarks(MarkCache * cache, bool save_in_cache, bool is_null_stream)
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{
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std::string path;
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if (is_null_stream)
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path = path_prefix + ".null.mrk";
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else
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path = path_prefix + ".mrk";
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UInt128 key;
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if (cache)
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{
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key = cache->hash(path);
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marks = cache->get(key);
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if (marks)
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return;
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}
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/// Memory for marks must not be accounted as memory usage for query, because they are stored in shared cache.
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TemporarilyDisableMemoryTracker temporarily_disable_memory_tracker;
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size_t file_size = Poco::File(path).getSize();
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if (file_size % sizeof(MarkInCompressedFile) != 0)
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throw Exception("Size of " + path + " file is not divisable by size of MarkInCompressedFile structure.", ErrorCodes::CORRUPTED_DATA);
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size_t num_marks = file_size / sizeof(MarkInCompressedFile);
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marks = std::make_shared<MarksInCompressedFile>(num_marks);
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/// Read directly to marks.
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ReadBufferFromFile buffer(path, file_size, -1, reinterpret_cast<char *>(marks->data()));
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if (buffer.eof() || buffer.buffer().size() != file_size)
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throw Exception("Cannot read all marks from file " + path, ErrorCodes::CANNOT_READ_ALL_DATA);
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if (cache && save_in_cache)
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cache->set(key, marks);
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}
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void MergeTreeReader::Stream::seekToMark(size_t index)
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{
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MarkInCompressedFile mark = (*marks)[index];
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try
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{
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if (cached_buffer)
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cached_buffer->seek(mark.offset_in_compressed_file, mark.offset_in_decompressed_block);
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if (non_cached_buffer)
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non_cached_buffer->seek(mark.offset_in_compressed_file, mark.offset_in_decompressed_block);
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}
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catch (Exception & e)
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{
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/// Более хорошая диагностика.
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if (e.code() == ErrorCodes::ARGUMENT_OUT_OF_BOUND)
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e.addMessage("(while seeking to mark " + toString(index)
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+ " of column " + path_prefix + "; offsets are: "
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+ toString(mark.offset_in_compressed_file) + " "
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+ toString(mark.offset_in_decompressed_block) + ")");
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throw;
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}
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}
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void MergeTreeReader::addStream(const String & name, const IDataType & type, const MarkRanges & all_mark_ranges,
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const ReadBufferFromFileBase::ProfileCallback & profile_callback, clockid_t clock_type,
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size_t level)
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{
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String escaped_column_name = escapeForFileName(name);
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const DataTypeArray * type_arr = typeid_cast<const DataTypeArray *>(&type);
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bool data_file_exists = Poco::File(path + escaped_column_name + DATA_FILE_EXTENSION).exists();
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bool is_column_of_nested_type = type_arr && level == 0 && DataTypeNested::extractNestedTableName(name) != name;
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/** If data file is missing then we will not try to open it.
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* It is necessary since it allows to add new column to structure of the table without creating new files for old parts.
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* But we should try to load offset data for array columns of Nested subtable (their data will be filled by default value).
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*/
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if (!data_file_exists && !is_column_of_nested_type)
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return;
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if (type.isNullable())
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{
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/// First create the stream that handles the null map of the given column.
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const DataTypeNullable & nullable_type = static_cast<const DataTypeNullable &>(type);
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const IDataType & nested_type = *nullable_type.getNestedType();
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std::string filename = name + NULL_MAP_EXTENSION;
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streams.emplace(filename, std::make_unique<Stream>(
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path + escaped_column_name, NULL_MAP_EXTENSION, uncompressed_cache, mark_cache, save_marks_in_cache,
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all_mark_ranges, aio_threshold, max_read_buffer_size, profile_callback, clock_type));
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/// Then create the stream that handles the data of the given column.
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addStream(name, nested_type, all_mark_ranges, profile_callback, clock_type, level);
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}
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/// Для массивов используются отдельные потоки для размеров.
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else if (type_arr)
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{
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String size_name = DataTypeNested::extractNestedTableName(name)
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+ ARRAY_SIZES_COLUMN_NAME_SUFFIX + toString(level);
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String escaped_size_name = escapeForFileName(DataTypeNested::extractNestedTableName(name))
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+ ARRAY_SIZES_COLUMN_NAME_SUFFIX + toString(level);
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String size_path = path + escaped_size_name + DATA_FILE_EXTENSION;
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/// We don't have neither offsets neither data -> skipping, default values will be filled after
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if (!data_file_exists && !Poco::File(size_path).exists())
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return;
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if (!streams.count(size_name))
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streams.emplace(size_name, std::make_unique<Stream>(
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path + escaped_size_name, DATA_FILE_EXTENSION, uncompressed_cache, mark_cache, save_marks_in_cache,
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all_mark_ranges, aio_threshold, max_read_buffer_size, profile_callback, clock_type));
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if (data_file_exists)
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addStream(name, *type_arr->getNestedType(), all_mark_ranges, profile_callback, clock_type, level + 1);
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else
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streams.emplace(name, Stream::createEmptyPtr());
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}
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else
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streams.emplace(name, std::make_unique<Stream>(
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path + escaped_column_name, DATA_FILE_EXTENSION, uncompressed_cache, mark_cache, save_marks_in_cache,
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all_mark_ranges, aio_threshold, max_read_buffer_size, profile_callback, clock_type));
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}
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void MergeTreeReader::readData(const String & name, const IDataType & type, IColumn & column,
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size_t from_mark, size_t max_rows_to_read, size_t level, bool read_offsets)
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{
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if (type.isNullable())
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{
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/// First read from the null map.
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const DataTypeNullable & nullable_type = static_cast<const DataTypeNullable &>(type);
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const IDataType & nested_type = *nullable_type.getNestedType();
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ColumnNullable & nullable_col = static_cast<ColumnNullable &>(column);
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IColumn & nested_col = *nullable_col.getNestedColumn();
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std::string filename = name + NULL_MAP_EXTENSION;
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Stream & stream = *(streams.at(filename));
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stream.seekToMark(from_mark);
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IColumn & col8 = nullable_col.getNullMapConcreteColumn();
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DataTypeUInt8{}.deserializeBinaryBulk(col8, *stream.data_buffer, max_rows_to_read, 0);
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/// Then read data.
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readData(name, nested_type, nested_col, from_mark, max_rows_to_read, level, read_offsets);
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}
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else if (const DataTypeArray * type_arr = typeid_cast<const DataTypeArray *>(&type))
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{
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/// Для массивов требуется сначала десериализовать размеры, а потом значения.
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if (read_offsets)
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{
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Stream & stream = *streams[DataTypeNested::extractNestedTableName(name) + ARRAY_SIZES_COLUMN_NAME_SUFFIX + toString(level)];
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stream.seekToMark(from_mark);
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type_arr->deserializeOffsets(
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column,
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*stream.data_buffer,
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max_rows_to_read);
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}
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if (column.size())
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{
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ColumnArray & array = typeid_cast<ColumnArray &>(column);
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const size_t required_internal_size = array.getOffsets()[column.size() - 1];
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if (required_internal_size)
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{
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readData(
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name,
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*type_arr->getNestedType(),
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array.getData(),
|
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from_mark,
|
||
required_internal_size - array.getData().size(),
|
||
level + 1);
|
||
|
||
size_t read_internal_size = array.getData().size();
|
||
|
||
/** Исправление для ошибочно записанных пустых файлов с данными массива.
|
||
* Такое бывает после ALTER с добавлением новых столбцов во вложенную структуру данных.
|
||
*/
|
||
if (required_internal_size != read_internal_size)
|
||
{
|
||
if (read_internal_size != 0)
|
||
LOG_ERROR((&Logger::get("MergeTreeReader")),
|
||
"Internal size of array " + name + " doesn't match offsets: corrupted data, filling with default values.");
|
||
|
||
array.getDataPtr() = dynamic_cast<IColumnConst &>(
|
||
*type_arr->getNestedType()->createConstColumn(
|
||
required_internal_size,
|
||
type_arr->getNestedType()->getDefault())).convertToFullColumn();
|
||
|
||
/** NOTE Можно было бы занулять этот столбец, чтобы он не добавлялся в блок,
|
||
* а впоследствии создавался с более правильными (из определения таблицы) значениями по-умолчанию.
|
||
*/
|
||
}
|
||
}
|
||
}
|
||
}
|
||
else
|
||
{
|
||
Stream & stream = *streams[name];
|
||
|
||
/// It means that data column of array column will be empty, and it will be replaced by const data column
|
||
if (stream.isEmpty())
|
||
return;
|
||
|
||
double & avg_value_size_hint = avg_value_size_hints[name];
|
||
stream.seekToMark(from_mark);
|
||
type.deserializeBinaryBulk(column, *stream.data_buffer, max_rows_to_read, avg_value_size_hint);
|
||
|
||
/// Вычисление подсказки о среднем размере значения.
|
||
size_t column_size = column.size();
|
||
if (column_size)
|
||
{
|
||
double current_avg_value_size = static_cast<double>(column.byteSize()) / column_size;
|
||
|
||
/// Эвристика, чтобы при изменениях, значение avg_value_size_hint быстро росло, но медленно уменьшалось.
|
||
if (current_avg_value_size > avg_value_size_hint)
|
||
avg_value_size_hint = current_avg_value_size;
|
||
else if (current_avg_value_size * 2 < avg_value_size_hint)
|
||
avg_value_size_hint = (current_avg_value_size + avg_value_size_hint * 3) / 4;
|
||
}
|
||
}
|
||
}
|
||
|
||
|
||
void MergeTreeReader::fillMissingColumnsImpl(Block & res, const Names & ordered_names, bool always_reorder)
|
||
{
|
||
if (!res)
|
||
throw Exception("Empty block passed to fillMissingColumnsImpl", ErrorCodes::LOGICAL_ERROR);
|
||
|
||
try
|
||
{
|
||
/** Для недостающих столбцов из вложенной структуры нужно создавать не столбец пустых массивов, а столбец массивов
|
||
* правильных длин.
|
||
* TODO: Если для какой-то вложенной структуры были запрошены только отсутствующие столбцы, для них вернутся пустые
|
||
* массивы, даже если в куске есть смещения для этой вложенной структуры. Это можно исправить.
|
||
* NOTE: Похожий код есть в Block::addDefaults, но он немного отличается.
|
||
*/
|
||
|
||
/// Сначала запомним столбцы смещений для всех массивов в блоке.
|
||
OffsetColumns offset_columns;
|
||
for (size_t i = 0; i < res.columns(); ++i)
|
||
{
|
||
const ColumnWithTypeAndName & column = res.safeGetByPosition(i);
|
||
|
||
IColumn * observed_column;
|
||
std::string column_name;
|
||
if (column.column->isNullable())
|
||
{
|
||
ColumnNullable & nullable_col = static_cast<ColumnNullable &>(*(column.column));
|
||
observed_column = nullable_col.getNestedColumn().get();
|
||
column_name = observed_column->getName();
|
||
}
|
||
else
|
||
{
|
||
observed_column = column.column.get();
|
||
column_name = column.name;
|
||
}
|
||
|
||
if (const ColumnArray * array = typeid_cast<const ColumnArray *>(observed_column))
|
||
{
|
||
String offsets_name = DataTypeNested::extractNestedTableName(column_name);
|
||
auto & offsets_column = offset_columns[offsets_name];
|
||
|
||
/// Если почему-то есть разные столбцы смещений для одной вложенной структуры, то берём непустой.
|
||
if (!offsets_column || offsets_column->empty())
|
||
offsets_column = array->getOffsetsColumn();
|
||
}
|
||
}
|
||
|
||
auto should_evaluate_defaults = false;
|
||
auto should_sort = always_reorder;
|
||
|
||
for (const auto & requested_column : columns)
|
||
{
|
||
/// insert default values only for columns without default expressions
|
||
if (!res.has(requested_column.name))
|
||
{
|
||
should_sort = true;
|
||
if (storage.column_defaults.count(requested_column.name) != 0)
|
||
{
|
||
should_evaluate_defaults = true;
|
||
continue;
|
||
}
|
||
|
||
ColumnWithTypeAndName column_to_add;
|
||
column_to_add.name = requested_column.name;
|
||
column_to_add.type = requested_column.type;
|
||
|
||
String offsets_name = DataTypeNested::extractNestedTableName(column_to_add.name);
|
||
if (offset_columns.count(offsets_name))
|
||
{
|
||
ColumnPtr offsets_column = offset_columns[offsets_name];
|
||
DataTypePtr nested_type = typeid_cast<DataTypeArray &>(*column_to_add.type).getNestedType();
|
||
size_t nested_rows = offsets_column->empty() ? 0
|
||
: typeid_cast<ColumnUInt64 &>(*offsets_column).getData().back();
|
||
|
||
ColumnPtr nested_column = dynamic_cast<IColumnConst &>(*nested_type->createConstColumn(
|
||
nested_rows, nested_type->getDefault())).convertToFullColumn();
|
||
|
||
column_to_add.column = std::make_shared<ColumnArray>(nested_column, offsets_column);
|
||
}
|
||
else
|
||
{
|
||
/** Нужно превратить константный столбец в полноценный, так как в части блоков (из других кусков),
|
||
* он может быть полноценным (а то интерпретатор может посчитать, что он константный везде).
|
||
*/
|
||
column_to_add.column = dynamic_cast<IColumnConst &>(*column_to_add.type->createConstColumn(
|
||
res.rows(), column_to_add.type->getDefault())).convertToFullColumn();
|
||
}
|
||
|
||
res.insert(std::move(column_to_add));
|
||
}
|
||
}
|
||
|
||
/// evaluate defaulted columns if necessary
|
||
if (should_evaluate_defaults)
|
||
evaluateMissingDefaults(res, columns, storage.column_defaults, storage.context);
|
||
|
||
/// sort columns to ensure consistent order among all blocks
|
||
if (should_sort)
|
||
{
|
||
Block ordered_block;
|
||
|
||
for (const auto & name : ordered_names)
|
||
if (res.has(name))
|
||
ordered_block.insert(res.getByName(name));
|
||
|
||
std::swap(res, ordered_block);
|
||
}
|
||
}
|
||
catch (Exception & e)
|
||
{
|
||
/// Более хорошая диагностика.
|
||
e.addMessage("(while reading from part " + path + ")");
|
||
throw;
|
||
}
|
||
}
|
||
|
||
}
|