From e37c42c56cba01de045b30035d02871a21bcee0f Mon Sep 17 00:00:00 2001
From: Azat Khuzhin <a3at.mail@gmail.com>
Date: Sat, 1 Aug 2020 02:55:08 +0300
Subject: [PATCH] Fix logging in MergeTreeDataSelectExecutor for multiple
 threads (attach to thread group)

---
 .../MergeTree/MergeTreeDataSelectExecutor.cpp        | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp b/src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp
index dc32e225697..7ac8ca6143b 100644
--- a/src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp
+++ b/src/Storages/MergeTree/MergeTreeDataSelectExecutor.cpp
@@ -1,4 +1,5 @@
 #include <boost/rational.hpp>   /// For calculations related to sampling coefficients.
+#include <ext/scope_guard.h>
 #include <optional>
 
 #include <Poco/File.h>
@@ -613,7 +614,16 @@ Pipes MergeTreeDataSelectExecutor::readFromParts(
             ThreadPool pool(num_threads);
 
             for (size_t part_index = 0; part_index < parts.size(); ++part_index)
-                pool.scheduleOrThrowOnError([&, part_index] { process_part(part_index); });
+                pool.scheduleOrThrowOnError([&, part_index, thread_group = CurrentThread::getGroup()] {
+                    SCOPE_EXIT(
+                        if (thread_group)
+                            CurrentThread::detachQueryIfNotDetached();
+                    );
+                    if (thread_group)
+                        CurrentThread::attachTo(thread_group);
+
+                    process_part(part_index);
+                });
 
             pool.wait();
         }