diff --git a/dbms/src/Processors/Executors/PipelineExecutor.cpp b/dbms/src/Processors/Executors/PipelineExecutor.cpp
index 9013b83486a..6addec11975 100644
--- a/dbms/src/Processors/Executors/PipelineExecutor.cpp
+++ b/dbms/src/Processors/Executors/PipelineExecutor.cpp
@@ -11,6 +11,10 @@
 #include <Processors/ISource.h>
 #include <Common/setThreadName.h>
 
+#if !defined(__APPLE__) && !defined(__FreeBSD__)
+#include <sched.h>
+#endif
+
 namespace DB
 {
 
@@ -452,6 +456,17 @@ void PipelineExecutor::execute(size_t num_threads)
 
 void PipelineExecutor::executeSingleThread(size_t thread_num, size_t num_threads)
 {
+#if !defined(__APPLE__) && !defined(__FreeBSD__)
+    /// Specify CPU core for thread if can.
+    /// It may reduce the number of context swithches.
+    cpu_set_t cpu_set;
+    CPU_ZERO(&cpu_set);
+    CPU_SET(thread_num, &cpu_set);
+    if (sched_setaffinity(0, sizeof(cpu_set_t), &cpu_set) == -1)
+        LOG_TRACE(log, "Cannot set affinity for thread " << num_threads);
+
+#endif
+
     UInt64 total_time_ns = 0;
     UInt64 execution_time_ns = 0;
     UInt64 processing_time_ns = 0;
diff --git a/dbms/src/Processors/Formats/Impl/MySQLOutputFormat.cpp b/dbms/src/Processors/Formats/Impl/MySQLOutputFormat.cpp
index b04de32ca5a..b948422a930 100644
--- a/dbms/src/Processors/Formats/Impl/MySQLOutputFormat.cpp
+++ b/dbms/src/Processors/Formats/Impl/MySQLOutputFormat.cpp
@@ -47,6 +47,9 @@ void MySQLOutputFormat::initialize()
 
 void MySQLOutputFormat::consume(Chunk chunk)
 {
+
+    initialize();
+
     for (size_t i = 0; i < chunk.getNumRows(); i++)
     {
         ProtocolText::ResultsetRow row_packet(data_types, chunk.getColumns(), i);