Method describeActions

src/Processors/QueryPlan/ReadFromMergeTree.cpp:4054–4177

}

void ReadFromMergeTree::describeActions(FormatSettings & format_settings) const
{
    const auto & result = getAnalysisResult();
    std::string prefix = format_settings.detail_prefix;
    std::string_view read_type_label = format_settings.pretty ? "Read type: " : "ReadType: ";
    format_settings.out << prefix << read_type_label << readTypeToString(result.read_type) << '\n';

    if (!result.index_stats.empty())
    {
        std::string_view delimiter = format_settings.pretty ? " | " : "\n";
        format_settings.out << prefix << "Parts: " << result.index_stats.back().num_parts_after << delimiter;
        format_settings.out << (format_settings.pretty ? "" : prefix) << "Granules: " << result.index_stats.back().num_granules_after << '\n';
    }

    if (output_each_partition_through_separate_port)
        format_settings.out << prefix << "Read each partition through separate port: 1\n";

    if (format_settings.pretty)
        QueryPlanFormat::formatOutputColumns(format_settings.pretty_names, format_settings.out, *this, prefix);

    if (query_info.prewhere_info || query_info.row_level_filter)
    {
        if (!format_settings.pretty)
        {
            format_settings.out << prefix << "Prewhere info" << '\n';
            if (query_info.prewhere_info)
                format_settings.out << prefix << "Need filter: " << query_info.prewhere_info->need_filter << '\n';

            prefix.push_back(format_settings.indent_char);
            prefix.push_back(format_settings.indent_char);
        }
    }

    if (query_info.prewhere_info)
    {
        const auto pretty_expression = format_settings.pretty
            ? QueryPlanFormat::formatColumnPretty(query_info.prewhere_info->prewhere_column_name, format_settings.pretty_names)
            : String{};

        if (!format_settings.pretty || !pretty_expression.empty())
        {
            format_settings.out << prefix << "Prewhere filter" << '\n';
            format_settings.out << prefix << "Prewhere filter column: "
                                << (format_settings.pretty ? pretty_expression : query_info.prewhere_info->prewhere_column_name);
            if (!format_settings.pretty && query_info.prewhere_info->remove_prewhere_column)
                format_settings.out << " (removed)";
            format_settings.out << '\n';
        }

        if (format_settings.pretty)
        {
            const auto annotation = QueryPlanFormat::getColumnAnnotation(query_info.prewhere_info->prewhere_column_name, format_settings);
            if (!annotation.empty())
                format_settings.out << prefix << annotation << '\n';
        }

        if (!format_settings.compact)
        {