Use separate default settings for clickhouse-local

There are already two of them:
- storage_file_read_method can use mmap method for clickhouse-local
- there is no sense in disabling allow_introspection_functions for
  clickhouse-local since it can hurt only itself

And likely there will be more, once the infrastructure will be there.

Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>

src/Core/Settings.h

@@ -657,7 +657,7 @@ class IColumn;
     M(UInt64, function_range_max_elements_in_block, 500000000, "Maximum number of values generated by function 'range' per block of data (sum of array sizes for every row in a block, see also 'max_block_size' and 'min_insert_block_size_rows'). It is a safety threshold.", 0) \
     M(ShortCircuitFunctionEvaluation, short_circuit_function_evaluation, ShortCircuitFunctionEvaluation::ENABLE, "Setting for short-circuit function evaluation configuration. Possible values: 'enable' - use short-circuit function evaluation for functions that are suitable for it, 'disable' - disable short-circuit function evaluation, 'force_enable' - use short-circuit function evaluation for all functions.", 0) \
     \
-    M(LocalFSReadMethod, storage_file_read_method, LocalFSReadMethod::mmap, "Method of reading data from storage file, one of: read, pread, mmap. The mmap method does not apply to clickhouse-server (it's intended for clickhouse-local).", 0) \
+    M(LocalFSReadMethod, storage_file_read_method, LocalFSReadMethod::pread, "Method of reading data from storage file, one of: read, pread, mmap. The mmap method does not apply to clickhouse-server (it's intended for clickhouse-local).", 0) \
     M(String, local_filesystem_read_method, "pread_threadpool", "Method of reading data from local filesystem, one of: read, pread, mmap, io_uring, pread_threadpool. The 'io_uring' method is experimental and does not work for Log, TinyLog, StripeLog, File, Set and Join, and other tables with append-able files in presence of concurrent reads and writes.", 0) \
     M(String, remote_filesystem_read_method, "threadpool", "Method of reading data from remote filesystem, one of: read, threadpool.", 0) \
     M(Bool, local_filesystem_read_prefetch, false, "Should use prefetching when reading data from local filesystem.", 0) \

src/Core/SettingsOverridesLocal.cpp

@@ -0,0 +1,13 @@
+#include <Core/SettingsOverridesLocal.h>
+#include <Core/Settings.h>
+
+namespace DB
+{
+
+void applySettingsOverridesForLocal(Settings & settings)
+{
+    settings.allow_introspection_functions = true;
+    settings.storage_file_read_method = LocalFSReadMethod::mmap;
+}
+
+}

src/Core/SettingsOverridesLocal.h

@@ -0,0 +1,11 @@
+#pragma once
+
+namespace DB
+{
+
+struct Settings;
+
+/// Update some settings defaults for clickhouse-local
+void applySettingsOverridesForLocal(Settings & settings);
+
+}

src/Interpreters/Context.cpp

@@ -48,6 +48,7 @@
 #include <Interpreters/PreparedSets.h>
 #include <Core/Settings.h>
 #include <Core/SettingsQuirks.h>
+#include <Core/SettingsOverridesLocal.h>
 #include <Access/AccessControl.h>
 #include <Access/ContextAccess.h>
 #include <Access/EnabledRolesInfo.h>
@@ -3646,6 +3647,8 @@ void Context::setDefaultProfiles(const Poco::Util::AbstractConfiguration & confi
     setCurrentProfile(shared->system_profile_name);
 
     applySettingsQuirks(settings, &Poco::Logger::get("SettingsQuirks"));
+    if (shared->application_type == ApplicationType::LOCAL)
+        applySettingsOverridesForLocal(settings);
 
     shared->buffer_profile_name = config.getString("buffer_profile", shared->system_profile_name);
     buffer_context = Context::createCopy(shared_from_this());

tests/queries/0_stateless/02800_clickhouse_local_default_settings.reference

@@ -0,0 +1,2 @@
+allow_introspection_functions	1
+storage_file_read_method	mmap

tests/queries/0_stateless/02800_clickhouse_local_default_settings.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+# Tags: no-random-settings, no-random-merge-tree-settings
+
+CUR_DIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+# shellcheck source=../shell_config.sh
+. "$CUR_DIR"/../shell_config.sh
+
+$CLICKHOUSE_LOCAL -q "select name, value from system.settings where changed"