Try fix tests.

src/Interpreters/InterpreterSelectQuery.cpp

@@ -1439,8 +1439,6 @@ void InterpreterSelectQuery::executeFetchColumns(
     if (!max_block_size)
         throw Exception("Setting 'max_block_size' cannot be zero", ErrorCodes::PARAMETER_OUT_OF_BOUND);
 
-    query_plan.setMaxThreads(max_threads_execute_query);
-
     /// Initialize the initial data streams to which the query transforms are superimposed. Table or subquery or prepared input?
     if (query_plan.isInitialized())
     {
@@ -1542,6 +1540,10 @@ void InterpreterSelectQuery::executeFetchColumns(
     else
         throw Exception("Logical error in InterpreterSelectQuery: nowhere to read", ErrorCodes::LOGICAL_ERROR);
 
+    /// Specify the number of threads only if it wasn't specified in storage.
+    if (!query_plan.getMaxThreads())
+        query_plan.setMaxThreads(max_threads_execute_query);
+
     /// Aliases in table declaration.
     if (processing_stage == QueryProcessingStage::FetchColumns && alias_actions)
     {

src/Processors/QueryPlan/QueryPlan.h

@@ -69,6 +69,7 @@ public:
     /// Set upper limit for the recommend number of threads. Will be applied to the newly-created pipelines.
     /// TODO: make it in a better way.
     void setMaxThreads(size_t max_threads_) { max_threads = max_threads_; }
+    size_t getMaxThreads() const { return max_threads; }
 
     void addInterpreterContext(std::shared_ptr<Context> context);