Function formatOutputColumns

src/Processors/QueryPlan/QueryPlanFormat.cpp:126–147

    }

    void formatOutputColumns(const std::unordered_map<String, PrettyColumnName> & pretty_names, WriteBuffer & out, const IQueryPlanStep & step, const String & prefix)
    {
        if (!step.hasOutputHeader() || step.getOutputHeader()->empty())
        {
            out << prefix << "Output: Empty\n";
            return;
        }

        out << prefix << "Output: ";
        bool first = true;
        for (const auto & elem : *step.getOutputHeader())
        {
            if (!first)
                out << ", ";
            first = false;
            auto it = pretty_names.find(elem.name);
            String pretty_name = it != pretty_names.end() ? it->second.expression : trimColumnIdentifier(elem.name);

            out << pretty_name;
        }
        out << '\n';
    }

    static PrettyColumnName formatFilterPretty(
        const ActionsDAG & dag,