Method executeSpecial

src/Interpreters/InterpreterShowStatsQuery.cpp:414–482

}

void InterpreterShowStatsQuery::executeSpecial()
{
    auto query = query_ptr->as<const ASTShowStatsQuery>();
    auto context = getContext();
    auto catalog = Statistics::createCatalogAdaptor(context);

    // when special, cache settings will be invalid
    if (collector_settings.cache_policy != StatisticsCachePolicy::Default)
    {
        throw Exception("cache policy is not supported for special functions", ErrorCodes::BAD_ARGUMENTS);
    }

    if (context->getSettingsRef().statistics_cache_policy != StatisticsCachePolicy::Default)
    {
        throw Exception(
            "statistics_cache_policy is not supported for special functions, must set it to default", ErrorCodes::BAD_ARGUMENTS);
    }

    // refactor this into an explicit command
    if (query->table == "__save")
    {
        catalog->checkHealth(/*is_write=*/false);
        auto db_name = context->resolveDatabase(query->database);
        auto path = context->getSettingsRef().graphviz_path.toString() + "/" + db_name + ".bin";

        writeDbStats(context, db_name, path);
    }
    else if (query->table == "__load")
    {
        catalog->checkHealth(/*is_write=*/true);
        auto db_name = query->database;
        if (db_name.empty())
            db_name = context->getCurrentDatabase();
        auto path = context->getSettingsRef().graphviz_path.toString() + "/" + db_name + ".bin";
        if (!std::filesystem::exists(path))
        {
            throw Exception("file " + path + " not exists", ErrorCodes::FILE_NOT_FOUND);
        }

        readDbStats(context, db_name, path);
    }
    else if (query->table == "__jsonsave")
    {
        catalog->checkHealth(/*is_write=*/false);
        auto db_name = query->database;
        if (db_name.empty())
            db_name = context->getCurrentDatabase();
        auto folder = context->getSettingsRef().graphviz_path.toString() + '/' + db_name;
        writeDbStatsToJson(context, db_name, folder);
    }
    else if (query->table == "__jsonload")
    {
        catalog->checkHealth(/*is_write=*/true);
        auto db_name = query->database;
        if (db_name.empty())
            db_name = context->getCurrentDatabase();
        auto path = context->getSettingsRef().graphviz_path.toString() + '/' + db_name + "/stats.json";
        if (!std::filesystem::exists(path))