Function executeSubQuery

src/Interpreters/executeSubQuery.cpp:133–167

}

void executeSubQuery(const String & query, ContextMutablePtr query_context, std::function<void(Block &)> proc_block, bool internal)
{
    modifyQueryContext(query_context, internal);

    std::exception_ptr exception;
    auto thread = ThreadFromGlobalPool([query_context = std::move(query_context), &query, proc_block, internal, &exception]() {
        try
        {
            CurrentThread::QueryScope query_scope{query_context};
            {
                auto block_io = executeQuery(query, query_context, internal);

                auto input_stream = block_io.getInputStream();
                input_stream->readPrefix();
                while (auto block = input_stream->read())
                {
                    if (block.rows() == 0)
                        continue;
                    proc_block(block);
                }
                input_stream->readSuffix();

                block_io.onFinish();
            }
        }
        catch (...)
        {
            exception = constructException(query_context);
        }
    });
    thread.join();

    if (exception)
        std::rethrow_exception(exception);
}

Block executeSubPipelineWithOneRow(
    const ASTPtr & query, ContextMutablePtr query_context, std::function<void(InterpreterSelectQueryUseOptimizer &)> pre_execute, bool tolerate_multi_rows)