From ca9bd647fbd97fd36de5e30778c824ae522e03c3 Mon Sep 17 00:00:00 2001
From: Alexey Milovidov <milovidov@clickhouse.com>
Date: Thu, 8 Aug 2024 04:52:18 +0200
Subject: [PATCH] Simplification

---
 src/Client/ClientBase.cpp | 43 +++++++--------------------------------
 1 file changed, 7 insertions(+), 36 deletions(-)

diff --git a/src/Client/ClientBase.cpp b/src/Client/ClientBase.cpp
index 62a008bc88c..a305278fb4d 100644
--- a/src/Client/ClientBase.cpp
+++ b/src/Client/ClientBase.cpp
@@ -1877,48 +1877,19 @@ void ClientBase::processParsedSingleQuery(const String & full_query, const Strin
     profile_events.watch.restart();
 
     {
-        /// Temporarily apply query settings to context.
-        std::optional<Settings> old_settings;
-        SCOPE_EXIT_SAFE({
-            if (old_settings)
-                client_context->setSettings(*old_settings);
+        /// Temporarily apply query settings to the context.
+        Settings old_settings = client_context->getSettingsCopy();
+        SCOPE_EXIT_SAFE(
+        {
+            client_context->setSettings(old_settings);
         });
-
-        auto apply_query_settings = [&](const IAST & settings_ast)
-        {
-            if (!old_settings)
-                old_settings.emplace(client_context->getSettingsRef());
-            client_context->applySettingsChanges(settings_ast.as<ASTSetQuery>()->changes);
-            client_context->resetSettingsToDefaultValue(settings_ast.as<ASTSetQuery>()->default_settings);
-        };
-
-        const auto * insert = parsed_query->as<ASTInsertQuery>();
-        if (const auto * select = parsed_query->as<ASTSelectQuery>(); select && select->settings())
-            apply_query_settings(*select->settings());
-        else if (const auto * select_with_union = parsed_query->as<ASTSelectWithUnionQuery>())
-        {
-            const ASTs & children = select_with_union->list_of_selects->children;
-            if (!children.empty())
-            {
-                // On the client it is enough to apply settings only for the
-                // last SELECT, since the only thing that is important to apply
-                // on the client is format settings.
-                const auto * last_select = children.back()->as<ASTSelectQuery>();
-                if (last_select && last_select->settings())
-                {
-                    apply_query_settings(*last_select->settings());
-                }
-            }
-        }
-        else if (const auto * query_with_output = parsed_query->as<ASTQueryWithOutput>(); query_with_output && query_with_output->settings_ast)
-            apply_query_settings(*query_with_output->settings_ast);
-        else if (insert && insert->settings_ast)
-            apply_query_settings(*insert->settings_ast);
+        InterpreterSetQuery::applySettingsFromQuery(parsed_query, client_context);
 
         if (!connection->checkConnected(connection_parameters.timeouts))
             connect();
 
         ASTPtr input_function;
+        const auto * insert = parsed_query->as<ASTInsertQuery>();
         if (insert && insert->select)
             insert->tryFindInputFunction(input_function);