Method writeTempPartImpl

src/Storages/MergeTree/MergeTreeDataWriter.cpp:674–1029

}

MergeTreeTemporaryPartPtr MergeTreeDataWriter::writeTempPartImpl(
    BlockWithPartition & block_with_partition,
    StorageMetadataPtr metadata_snapshot,
    String partition_id,
    SourcePartsSetForPatch source_parts_set,
    ContextPtr context,
    UInt64 block_number)
{
    auto temp_part = std::make_unique<MergeTreeTemporaryPart>();
    Block & block = *block_with_partition.block;
    MergeTreePartition & partition = block_with_partition.partition;

    const auto & data_settings = data.getSettings();
    const auto & global_settings = context->getSettingsRef();

    auto columns = metadata_snapshot->getColumns().getAllPhysical().filter(block.getNames());

    /// Do not write _block_number and _block_offset for 0-level parts: block number is not known on this step.
    const auto minmax_columns = MergeTreeData::getMinMaxColumns(metadata_snapshot->getPartitionKey(), data_settings, MergeTreePartMinMaxIndexColumns::PARTITION_KEY_ONLY);
    auto minmax_idx = std::make_shared<IMergeTreeDataPart::MinMaxIndex>();
    minmax_idx->update(block, minmax_columns);

    const bool optimize_on_insert = !isPatchPartitionId(partition_id)
        && global_settings[Setting::optimize_on_insert]
        && data.merging_params.mode != MergeTreeData::MergingParams::Ordinary;
    UInt32 new_part_level = optimize_on_insert ? 1 : 0;
    MergeTreePartInfo new_part_info(std::move(partition_id), block_number, block_number, new_part_level);

    if (!source_parts_set.empty())
        new_part_info.mutation = source_parts_set.getMaxDataVersion();

    String part_name;
    if (data.format_version < MERGE_TREE_DATA_MIN_FORMAT_VERSION_WITH_CUSTOM_PARTITIONING)
    {
        DayNum min_date(static_cast<DayNum::UnderlyingType>(minmax_idx->hyperrectangle[data.minmax_idx_date_column_pos].left.safeGet<UInt64>()));
        DayNum max_date(static_cast<DayNum::UnderlyingType>(minmax_idx->hyperrectangle[data.minmax_idx_date_column_pos].right.safeGet<UInt64>()));

        const auto & date_lut = DateLUT::serverTimezoneInstance();

        auto min_month = date_lut.toNumYYYYMM(min_date);
        auto max_month = date_lut.toNumYYYYMM(max_date);

        if (min_month != max_month)
            throw Exception(ErrorCodes::LOGICAL_ERROR, "Part spans more than one month.");

        part_name = new_part_info.getPartNameV0(min_date, max_date);
    }
    else
        part_name = new_part_info.getPartNameV1();

    std::string temp_prefix = "tmp_insert_";
    const auto & temp_postfix = data.getPostfixForTempInsertName();
    if (!temp_postfix.empty())
        temp_prefix += temp_postfix + "_";

    std::string part_dir = temp_prefix + part_name;
    temp_part->temporary_directory_lock = data.getTemporaryPartDirectoryHolder(part_dir);