Apply linter changes

.clang-tidy

@@ -116,7 +116,6 @@ Checks: [
   '-readability-avoid-unconditional-preprocessor-if',
   '-readability-braces-around-statements',
   '-readability-convert-member-functions-to-static',
-  '-readability-else-after-return',
   '-readability-function-cognitive-complexity',
   '-readability-function-size',
   '-readability-identifier-length',

base/base/DecomposedFloat.h

@@ -110,7 +110,6 @@ struct DecomposedFloat
         {
             if (!isNegative())
                 return rhs > 0 ? -1 : 1;
-            else
             return rhs >= 0 ? -1 : 1;
         }
 
@@ -128,7 +127,6 @@ struct DecomposedFloat
 
                 if (mantissa() == 0)
                     return 0;
-                else
                 return -1;
             }
         }
@@ -169,7 +167,6 @@ struct DecomposedFloat
         /// Float has no fractional part means that the numbers are equal.
         if (large_and_always_integer || (mantissa() & ((1ULL << (Traits::mantissa_bits - normalizedExponent())) - 1)) == 0)
             return 0;
-        else
         /// Float has fractional part means its abs value is larger.
         return isNegative() ? -1 : 1;
     }

base/base/JSON.cpp

@@ -205,7 +205,6 @@ JSON::ElementType JSON::getType() const
             Pos after_string = skipString();
             if (after_string < ptr_end && *after_string == ':')
                 return TYPE_NAME_VALUE_PAIR;
-            else
             return TYPE_STRING;
         }
         default:
@@ -474,7 +473,6 @@ JSON::Pos JSON::searchField(const char * data, size_t size) const
 
     if (it == end())
         return nullptr;
-    else
     return it->data();
 }
 
@@ -487,7 +485,7 @@ bool JSON::hasEscapes() const
 
     if (*pos == '"')
         return false;
-    else if (*pos == '\\')
+    if (*pos == '\\')
         return true;
     throw JSONException("JSON: unexpected end of data.");
 }
@@ -503,7 +501,7 @@ bool JSON::hasSpecialChars() const
 
     if (*pos == '"')
         return false;
-    else if (pos < ptr_end)
+    if (pos < ptr_end)
         return true;
     throw JSONException("JSON: unexpected end of data.");
 }
@@ -682,9 +680,8 @@ double JSON::toDouble() const
 
     if (type == TYPE_NUMBER)
         return getDouble();
-    else if (type == TYPE_STRING)
+    if (type == TYPE_STRING)
         return JSON(ptr_begin + 1, ptr_end, level + 1).getDouble();
-    else
     throw JSONException("JSON: cannot convert value to double.");
 }
 
@@ -694,9 +691,8 @@ Int64 JSON::toInt() const
 
     if (type == TYPE_NUMBER)
         return getInt();
-    else if (type == TYPE_STRING)
+    if (type == TYPE_STRING)
         return JSON(ptr_begin + 1, ptr_end, level + 1).getInt();
-    else
     throw JSONException("JSON: cannot convert value to signed integer.");
 }
 
@@ -706,9 +702,8 @@ UInt64 JSON::toUInt() const
 
     if (type == TYPE_NUMBER)
         return getUInt();
-    else if (type == TYPE_STRING)
+    if (type == TYPE_STRING)
         return JSON(ptr_begin + 1, ptr_end, level + 1).getUInt();
-    else
     throw JSONException("JSON: cannot convert value to unsigned integer.");
 }
 
@@ -718,11 +713,9 @@ std::string JSON::toString() const
 
     if (type == TYPE_STRING)
         return getString();
-    else
-    {
+
     Pos pos = skipElement();
     return std::string(ptr_begin, pos - ptr_begin);
-    }
 }
 
 

base/base/JSON.h

@@ -203,9 +203,7 @@ T JSON::getWithDefault(const std::string & key, const T & default_) const
 
         if (key_json.isType<T>())
             return key_json.get<T>();
-        else
         return default_;
     }
-    else
     return default_;
 }

base/base/StringRef.h

@@ -151,19 +151,19 @@ inline bool memequalWide(const char * p1, const char * p2, size_t size)
             return unalignedLoad<uint64_t>(p1) == unalignedLoad<uint64_t>(p2)
                 && unalignedLoad<uint64_t>(p1 + size - 8) == unalignedLoad<uint64_t>(p2 + size - 8);
         }
-        else if (size >= 4)
+        if (size >= 4)
         {
             /// Chunks of 4..7 bytes.
             return unalignedLoad<uint32_t>(p1) == unalignedLoad<uint32_t>(p2)
                 && unalignedLoad<uint32_t>(p1 + size - 4) == unalignedLoad<uint32_t>(p2 + size - 4);
         }
-        else if (size >= 2)
+        if (size >= 2)
         {
             /// Chunks of 2..3 bytes.
             return unalignedLoad<uint16_t>(p1) == unalignedLoad<uint16_t>(p2)
                 && unalignedLoad<uint16_t>(p1 + size - 2) == unalignedLoad<uint16_t>(p2 + size - 2);
         }
-        else if (size >= 1)
+        if (size >= 1)
         {
             /// A single byte.
             return *p1 == *p2;

base/base/argsToConfig.cpp

@@ -53,10 +53,9 @@ void argsToConfig(const Poco::Util::Application::ArgVec & argv,
                 key = arg.substr(key_start);
             continue;
         }
-        else
-        {
+
         key = "";
-        }
+
 
         if (key_start == std::string::npos)
             continue;

base/base/find_symbols.h

@@ -330,7 +330,6 @@ inline const char * find_first_symbols_dispatch(const char * begin, const char *
 #if defined(__SSE4_2__)
     if (sizeof...(symbols) >= 5)
         return find_first_symbols_sse42<positive, return_mode, sizeof...(symbols), symbols...>(begin, end);
-    else
 #endif
     return find_first_symbols_sse2<positive, return_mode, symbols...>(begin, end);
 }
@@ -341,7 +340,6 @@ inline const char * find_first_symbols_dispatch(const std::string_view haystack,
 #if defined(__SSE4_2__)
     if (symbols.str.size() >= 5)
         return find_first_symbols_sse42<positive, return_mode>(haystack.begin(), haystack.end(), symbols);
-    else
 #endif
     return find_first_symbols_sse2<positive, return_mode>(haystack.begin(), haystack.end(), symbols.str.data(), symbols.str.size());
 }

base/base/getMemoryAmount.cpp

@@ -33,7 +33,6 @@ std::optional<uint64_t> getCgroupsV2MemoryLimit()
             uint64_t value;
             if (setting_file >> value)
                 return {value};
-            else
             return {}; /// e.g. the cgroups default "max"
         }
         current_cgroup = current_cgroup.parent_path();

programs/benchmark/Benchmark.cpp

@@ -445,8 +445,7 @@ private:
                     shutdown = true;
                     throw;
                 }
-                else
-                {
+
                 std::cerr << getCurrentExceptionMessage(print_stacktrace,
                     true /*check embedded stack trace*/) << std::endl;
 
@@ -454,7 +453,6 @@ private:
                 ++comparison_info_per_interval[info_index]->errors;
                 ++comparison_info_total[info_index]->errors;
             }
-            }
             // Count failed queries toward executed, so that we'd reach
             // max_iterations even if every run fails.
             ++queries_executed;

programs/client/Client.cpp

@@ -479,14 +479,11 @@ void Client::connect()
             break;
         }
         catch (const Exception & e)
-        {
-            if (e.code() == DB::ErrorCodes::AUTHENTICATION_FAILED)
         {
             /// This problem can't be fixed with reconnection so it is not attempted
+            if (e.code() == DB::ErrorCodes::AUTHENTICATION_FAILED)
                 throw;
-            }
-            else
-            {
+
             if (attempted_address_index == hosts_and_ports.size() - 1)
                 throw;
 
@@ -503,7 +500,6 @@ void Client::connect()
             }
         }
     }
-    }
 
     server_version = toString(server_version_major) + "." + toString(server_version_minor) + "." + toString(server_version_patch);
     load_suggestions = is_interactive && (server_revision >= Suggest::MIN_SERVER_REVISION) && !config().getBool("disable_suggestion", false);

programs/disks/CommandCopy.cpp

@@ -46,7 +46,7 @@ public:
                 path_from,
                 disk_from.getDisk()->getName());
         }
-        else if (disk_from.getDisk()->isFile(path_from))
+        if (disk_from.getDisk()->isFile(path_from))
         {
             auto target_location = getTargetLocation(path_from, disk_to, path_to);
             if (!disk_to.getDisk()->exists(target_location) || disk_to.getDisk()->isFile(target_location))
@@ -77,7 +77,7 @@ public:
             {
                 throw Exception(ErrorCodes::BAD_ARGUMENTS, "cannot overwrite non-directory {} with directory {}", path_to, target_location);
             }
-            else if (!disk_to.getDisk()->exists(target_location))
+            if (!disk_to.getDisk()->exists(target_location))
             {
                 disk_to.getDisk()->createDirectory(target_location);
             }

programs/disks/CommandList.cpp

@@ -72,13 +72,9 @@ private:
             auto path = [&]() -> String
             {
                 if (relative_path.ends_with("/"))
-                {
                     return relative_path + file_name;
-                }
-                else
-                {
+
                 return relative_path + "/" + file_name;
-                }
             }();
             if (disk.isDirectory(path))
             {

programs/disks/CommandMove.cpp

@@ -53,12 +53,10 @@ public:
                 {
                     throw Exception(ErrorCodes::BAD_ARGUMENTS, "cannot move '{}' to '{}': Directory not empty", path_from, target_location);
                 }
-                else
-                {
+
                 disk.getDisk()->moveDirectory(path_from, target_location);
             }
         }
-        }
         else if (!disk.getDisk()->exists(path_from))
         {
             throw Exception(

programs/disks/CommandRemove.cpp

@@ -32,17 +32,15 @@ public:
         {
             throw Exception(ErrorCodes::BAD_ARGUMENTS, "Path {} on disk {} doesn't exist", path, disk.getDisk()->getName());
         }
-        else if (disk.getDisk()->isDirectory(path))
+        if (disk.getDisk()->isDirectory(path))
         {
             if (!recursive)
             {
                 throw Exception(ErrorCodes::BAD_ARGUMENTS, "cannot remove '{}': Is a directory", path);
             }
-            else
-            {
+
             disk.getDisk()->removeRecursive(path);
         }
-        }
         else
         {
             disk.getDisk()->removeFileIfExists(path);

programs/disks/CommandWrite.cpp

@@ -33,14 +33,10 @@ public:
         auto in = [&]() -> std::unique_ptr<ReadBufferFromFileBase>
         {
             if (!path_from.has_value())
-            {
                 return std::make_unique<ReadBufferFromFileDescriptor>(STDIN_FILENO);
-            }
-            else
-            {
+
             String relative_path_from = disk.getRelativeFromRoot(path_from.value());
             return disk.getDisk()->readFile(relative_path_from, getReadSettings());
-            }
         }();
 
         auto out = disk.getDisk()->writeFile(path_to);

programs/disks/DisksApp.cpp

@@ -127,13 +127,12 @@ std::vector<String> DisksApp::getCompletions(const String & prefix) const
         }
         return getEmptyCompletion(command->command_name);
     }
-    else if (arguments.size() == 1)
+    if (arguments.size() == 1)
     {
         String command_prefix = arguments[0];
         return getCommandsToComplete(command_prefix);
     }
-    else
-    {
+
     String last_token = arguments.back();
     CommandPtr command;
     try
@@ -144,23 +143,17 @@ std::vector<String> DisksApp::getCompletions(const String & prefix) const
     {
         return {last_token};
     }
+
     std::vector<String> answer = {};
     if (command->command_name == "help")
-        {
         return getCommandsToComplete(last_token);
-        }
-        else
-        {
+
     answer = [&]() -> std::vector<String>
     {
         if (multidisk_commands.contains(command->command_name))
-                {
             return client->getAllFilesByPatternFromAllDisks(last_token);
-                }
-                else
-                {
+
         return client->getCurrentDiskWithPath().getAllFilesByPattern(last_token);
-                }
     }();
 
     for (const auto & disk_name : client->getAllDiskNames())
@@ -178,17 +171,14 @@ std::vector<String> DisksApp::getCompletions(const String & prefix) const
             answer.push_back(option_sign);
         }
     }
-        }
+
     if (!answer.empty())
     {
         std::sort(answer.begin(), answer.end());
         return answer;
     }
-        else
-        {
+
     return {last_token};
-        }
-    }
 }
 
 bool DisksApp::processQueryText(const String & text)
@@ -210,11 +200,11 @@ bool DisksApp::processQueryText(const String & text)
     catch (DB::Exception & err)
     {
         int code = getCurrentExceptionCode();
+
         if (code == ErrorCodes::LOGICAL_ERROR)
-        {
             throw std::move(err);
-        }
-        else if (code == ErrorCodes::BAD_ARGUMENTS)
+
+        if (code == ErrorCodes::BAD_ARGUMENTS)
         {
             std::cerr << err.message() << "\n"
                       << "\n";

programs/disks/DisksClient.cpp

@@ -49,10 +49,8 @@ std::vector<String> DiskWithPath::listAllFilesByPath(const String & any_path) co
         disk->listFiles(getRelativeFromRoot(any_path), file_names);
         return file_names;
     }
-    else
-    {
+
     return {};
-    }
 }
 
 std::vector<String> DiskWithPath::getAllFilesByPattern(const String & pattern) const
@@ -61,23 +59,15 @@ std::vector<String> DiskWithPath::getAllFilesByPattern(const String & pattern) c
     {
         auto slash_pos = pattern.find_last_of('/');
         if (slash_pos >= pattern.size())
-        {
             return {"", pattern};
-        }
-        else
-        {
+
         return {pattern.substr(0, slash_pos + 1), pattern.substr(slash_pos + 1, pattern.size() - slash_pos - 1)};
-        }
     }();
 
     if (!isDirectory(path_before))
-    {
         return {};
-    }
-    else
-    {
-        std::vector<String> file_names = listAllFilesByPath(path_before);
 
+    std::vector<String> file_names = listAllFilesByPath(path_before);
     std::vector<String> answer;
 
     for (const auto & file_name : file_names)
@@ -93,7 +83,6 @@ std::vector<String> DiskWithPath::getAllFilesByPattern(const String & pattern) c
         }
     }
     return answer;
-    }
 };
 
 void DiskWithPath::setPath(const String & any_path)

programs/disks/ICommand.cpp

@@ -39,13 +39,9 @@ DiskWithPath & ICommand::getDiskWithPath(DisksClient & client, const CommandLine
 {
     auto disk_name = getValueFromCommandLineOptionsWithOptional<String>(options, name);
     if (disk_name.has_value())
-    {
         return client.getDiskWithPath(disk_name.value());
-    }
-    else
-    {
+
     return client.getCurrentDiskWithPath();
-    }
 }
 
 }

programs/disks/ICommand.h

@@ -63,40 +63,28 @@ protected:
     static T getValueFromCommandLineOptionsThrow(const CommandLineOptions & options, const String & name)
     {
         if (options.count(name))
-        {
             return getValueFromCommandLineOptions<T>(options, name);
-        }
-        else
-        {
+
         throw DB::Exception(ErrorCodes::BAD_ARGUMENTS, "Mandatory argument '{}' is missing", name);
     }
-    }
 
     template <typename T>
     static T getValueFromCommandLineOptionsWithDefault(const CommandLineOptions & options, const String & name, const T & default_value)
     {
         if (options.count(name))
-        {
             return getValueFromCommandLineOptions<T>(options, name);
-        }
-        else
-        {
+
         return default_value;
     }
-    }
 
     template <typename T>
     static std::optional<T> getValueFromCommandLineOptionsWithOptional(const CommandLineOptions & options, const String & name)
     {
         if (options.count(name))
-        {
             return std::optional{getValueFromCommandLineOptions<T>(options, name)};
-        }
-        else
-        {
+
         return std::nullopt;
     }
-    }
 
     DiskWithPath & getDiskWithPath(DisksClient & client, const CommandLineOptions & options, const String & name);
 

programs/install/Install.cpp

@@ -110,7 +110,7 @@ static auto executeScript(const std::string & command, bool throw_on_error = fal
         sh->wait();
         return 0;
     }
-    else
+
     return sh->tryWait();
 }
 

programs/library-bridge/CatBoostLibraryHandlerFactory.cpp

@@ -26,8 +26,7 @@ CatBoostLibraryHandlerPtr CatBoostLibraryHandlerFactory::tryGetModel(const Strin
 
     if (found)
         return handler->second;
-    else
-    {
+
     if (create_if_not_found)
     {
         auto new_handler = std::make_shared<CatBoostLibraryHandler>(library_path, model_path);
@@ -36,7 +35,6 @@ CatBoostLibraryHandlerPtr CatBoostLibraryHandlerFactory::tryGetModel(const Strin
         return new_handler;
     }
     return nullptr;
-    }
 }
 
 void CatBoostLibraryHandlerFactory::removeModel(const String & model_path)

programs/library-bridge/LibraryBridgeHandlerFactory.cpp

@@ -25,7 +25,7 @@ std::unique_ptr<HTTPRequestHandler> LibraryBridgeHandlerFactory::createRequestHa
     {
         if (uri.getPath() == "/extdict_ping")
             return std::make_unique<ExternalDictionaryLibraryBridgeExistsHandler>(getContext());
-        else if (uri.getPath() == "/catboost_ping")
+        if (uri.getPath() == "/catboost_ping")
             return std::make_unique<CatBoostLibraryBridgeExistsHandler>(getContext());
     }
 
@@ -33,7 +33,7 @@ std::unique_ptr<HTTPRequestHandler> LibraryBridgeHandlerFactory::createRequestHa
     {
         if (uri.getPath() == "/extdict_request")
             return std::make_unique<ExternalDictionaryLibraryBridgeRequestHandler>(getContext());
-        else if (uri.getPath() == "/catboost_request")
+        if (uri.getPath() == "/catboost_request")
             return std::make_unique<CatBoostLibraryBridgeRequestHandler>(getContext());
     }
 

programs/library-bridge/LibraryBridgeHandlers.cpp

@@ -158,12 +158,10 @@ void ExternalDictionaryLibraryBridgeRequestHandler::handleRequest(HTTPServerRequ
                 out.finalize();
                 return;
             }
-            else
-            {
+
             LOG_TRACE(log, "Cannot clone from dictionary with id: {}, will call extDict_libNew instead", from_dictionary_id);
             lib_new = true;
         }
-        }
         if (lib_new)
         {
             auto & read_buf = request.getStream();

programs/obfuscator/Obfuscator.cpp

@@ -231,7 +231,7 @@ static Int64 transformSigned(Int64 x, UInt64 seed)
 {
     if (x >= 0)
         return transform(x, seed);
-    else
+
     return -transform(-x, seed);    /// It works Ok even for minimum signed number.
 }
 
@@ -1105,7 +1105,7 @@ public:
         {
             if (isUInt(data_type))
                 return std::make_unique<UnsignedIntegerModel>(seed);
-            else
+
             return std::make_unique<SignedIntegerModel>(seed);
         }
 

programs/odbc-bridge/getIdentifierQuote.cpp

@@ -39,11 +39,11 @@ IdentifierQuotingStyle getQuotingStyle(nanodbc::ConnectionHolderPtr connection)
     auto identifier_quote = getIdentifierQuote(connection);
     if (identifier_quote.empty())
         return IdentifierQuotingStyle::Backticks;
-    else if (identifier_quote[0] == '`')
+    if (identifier_quote[0] == '`')
         return IdentifierQuotingStyle::Backticks;
-    else if (identifier_quote[0] == '"')
+    if (identifier_quote[0] == '"')
         return IdentifierQuotingStyle::DoubleQuotes;
-    else
+
     throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
                     "Can not map quote identifier '{}' to IdentifierQuotingStyle value", identifier_quote);
 }

programs/odbc-bridge/validateODBCConnectionString.cpp

@@ -127,7 +127,7 @@ std::string validateODBCConnectionString(const std::string & connection_string)
 
         if (*pos == '{')
             return read_escaped_value();
-        else
+
         return read_plain_value();
     };
 
@@ -206,13 +206,11 @@ std::string validateODBCConnectionString(const std::string & connection_string)
                 reconstructed_connection_string.append(value_pos, next_pos - value_pos);
                 break;
             }
-            else
-            {
+
             reconstructed_connection_string.append(value_pos, next_pos - value_pos);
             reconstructed_connection_string.append("}}");
             value_pos = next_pos + 1;
         }
-        }
 
         reconstructed_connection_string += '}';
     };

src/Access/AccessBackup.cpp

@@ -116,16 +116,14 @@ namespace
                         reading_dependents = false;
                         continue;
                     }
-                    else if (line == "DEPENDENTS")
+                    if (line == "DEPENDENTS")
                     {
                         reading_dependents = true;
                         reading_dependencies = false;
                         continue;
                     }
-                    else if (line.empty())
-                    {
+                    if (line.empty())
                         continue;
-                    }
 
                     size_t separator1 = line.find('\t');
                     size_t separator2 = line.find('\t', separator1 + 1);

src/Access/AccessControl.cpp

@@ -134,7 +134,7 @@ public:
                             "' registered for user-defined settings",
                             String{setting_name}, boost::algorithm::join(registered_prefixes, "' or '"));
         }
-        else
+
         throw Exception(ErrorCodes::UNKNOWN_SETTING, "Unknown setting '{}'", String{setting_name});
     }
 
@@ -830,7 +830,6 @@ std::shared_ptr<const EnabledQuota> AccessControl::getAuthenticationQuota(
                                             quota_key,
                                             throw_if_client_key_empty);
     }
-    else
     return nullptr;
 }
 

src/Access/AccessRights.cpp

@@ -1483,16 +1483,16 @@ bool AccessRights::isGrantedImplHelper(const AccessRightsElement & element) cons
     {
         if (element.anyParameter())
             return isGrantedImpl<grant_option, wildcard>(element.access_flags);
-        else
+
         return isGrantedImpl<grant_option, wildcard>(element.access_flags, element.parameter);
     }
-    else if (element.anyDatabase())
+    if (element.anyDatabase())
         return isGrantedImpl<grant_option, wildcard>(element.access_flags);
-    else if (element.anyTable())
+    if (element.anyTable())
         return isGrantedImpl<grant_option, wildcard>(element.access_flags, element.database);
-    else if (element.anyColumn())
+    if (element.anyColumn())
         return isGrantedImpl<grant_option, wildcard>(element.access_flags, element.database, element.table);
-    else
+
     return isGrantedImpl<grant_option, wildcard>(element.access_flags, element.database, element.table, element.columns);
 }
 
@@ -1503,16 +1503,14 @@ bool AccessRights::isGrantedImpl(const AccessRightsElement & element) const
     {
         if (element.grant_option)
             return isGrantedImplHelper<true, true>(element);
-        else
+
         return isGrantedImplHelper<grant_option, true>(element);
     }
-    else
-    {
+
     if (element.grant_option)
         return isGrantedImplHelper<true, wildcard>(element);
-        else
+
     return isGrantedImplHelper<grant_option, wildcard>(element);
-    }
 }
 
 template <bool grant_option, bool wildcard>

src/Access/AuthenticationData.cpp

@@ -501,10 +501,9 @@ AuthenticationData AuthenticationData::fromAST(const ASTAuthenticationData & que
             auth_data.setPasswordHashBinary(AuthenticationData::Util::stringToDigest(value));
             return auth_data;
         }
-        else
-        {
+
         auth_data.setPasswordHashHex(value);
-        }
+
 
         if (query.type == AuthenticationType::SHA256_PASSWORD && args_size == 2)
         {

src/Access/Common/AccessFlags.cpp

@@ -247,7 +247,6 @@ namespace
                 const auto & unused_node = *(owned_nodes.begin()->second);
                 if (unused_node.node_type == UNKNOWN)
                     throw Exception(ErrorCodes::LOGICAL_ERROR, "Parent group '{}' not found", unused_node.keyword);
-                else
                 throw Exception(ErrorCodes::LOGICAL_ERROR, "Access type '{}' should have parent group", unused_node.keyword);
             }
         }

src/Access/Common/AllowedClientHosts.cpp

@@ -61,7 +61,7 @@ namespace
         {
             if (addr.family() == IPAddress::Family::IPv4 && addr_v6 == toIPv6(addr))
                 return true;
-            else if (addr.family() == IPAddress::Family::IPv6 && addr_v6 == addr)
+            if (addr.family() == IPAddress::Family::IPv6 && addr_v6 == addr)
                 return true;
         }
 
@@ -267,9 +267,8 @@ String AllowedClientHosts::IPSubnet::toString() const
     unsigned int prefix_length = mask.prefixLength();
     if (isMaskAllBitsOne())
         return prefix.toString();
-    else if (IPAddress{prefix_length, mask.family()} == mask)
+    if (IPAddress{prefix_length, mask.family()} == mask)
         return fs::path(prefix.toString()) / std::to_string(prefix_length);
-    else
     return fs::path(prefix.toString()) / mask.toString();
 }
 
@@ -575,11 +574,10 @@ bool AllowedClientHosts::contains(const IPAddress & client_address) const
         parseLikePattern(pattern, subnet, name, name_regexp);
         if (subnet)
             return check_subnet(*subnet);
-        else if (name)
+        if (name)
             return check_name(*name);
-        else if (name_regexp)
+        if (name_regexp)
             return check_name_regexp(*name_regexp);
-        else
         return false;
     };
 

src/Access/Common/QuotaDefs.cpp

@@ -28,7 +28,6 @@ String QuotaTypeInfo::valueToString(QuotaValue value) const
 {
     if (!(value % output_denominator))
         return std::to_string(value / output_denominator);
-    else
     return toString(static_cast<double>(value) / output_denominator);
 }
 
@@ -36,7 +35,6 @@ QuotaValue QuotaTypeInfo::stringToValue(const String & str) const
 {
     if (output_denominator == 1)
         return static_cast<QuotaValue>(parse<UInt64>(str));
-    else
     return static_cast<QuotaValue>(parse<Float64>(str) * output_denominator);
 }
 

src/Access/ContextAccess.cpp

@@ -728,7 +728,6 @@ bool ContextAccess::checkAccessImplHelper(const ContextPtr & context, AccessFlag
                     "For queries over HTTP, method GET implies readonly. "
                     "You should use method POST for modifying queries");
             }
-            else
             return access_denied(ErrorCodes::READONLY, "{}: Cannot execute query in readonly mode");
         }
     }
@@ -770,16 +769,16 @@ bool ContextAccess::checkAccessImplHelper(const ContextPtr & context, const Acce
     {
         if (element.anyParameter())
             return checkAccessImpl<throw_if_denied, grant_option, wildcard>(context, element.access_flags);
-        else
+
         return checkAccessImpl<throw_if_denied, grant_option, wildcard>(context, element.access_flags, element.parameter);
     }
-    else if (element.anyDatabase())
+    if (element.anyDatabase())
         return checkAccessImpl<throw_if_denied, grant_option, wildcard>(context, element.access_flags);
-    else if (element.anyTable())
+    if (element.anyTable())
         return checkAccessImpl<throw_if_denied, grant_option, wildcard>(context, element.access_flags, element.database);
-    else if (element.anyColumn())
+    if (element.anyColumn())
         return checkAccessImpl<throw_if_denied, grant_option, wildcard>(context, element.access_flags, element.database, element.table);
-    else
+
     return checkAccessImpl<throw_if_denied, grant_option, wildcard>(context, element.access_flags, element.database, element.table, element.columns);
 }
 
@@ -790,16 +789,14 @@ bool ContextAccess::checkAccessImpl(const ContextPtr & context, const AccessRigh
     {
         if (element.grant_option)
             return checkAccessImplHelper<throw_if_denied, true, true>(context, element);
-        else
+
         return checkAccessImplHelper<throw_if_denied, grant_option, true>(context, element);
     }
-    else
-    {
+
     if (element.grant_option)
         return checkAccessImplHelper<throw_if_denied, true, wildcard>(context, element);
-        else
+
     return checkAccessImplHelper<throw_if_denied, grant_option, wildcard>(context, element);
-    }
 }
 
 template <bool throw_if_denied, bool grant_option, bool wildcard>

src/Access/ContextAccessParams.cpp

@@ -89,9 +89,8 @@ bool operator ==(const ContextAccessParams & left, const ContextAccessParams & r
         {
             if (!x)
                 return !y;
-            else if (!y)
+            if (!y)
                 return false;
-            else
             return *x == *y;
         }
         else
@@ -132,22 +131,20 @@ bool operator <(const ContextAccessParams & left, const ContextAccessParams & ri
         {
             if (!x)
                 return y ? -1 : 0;
-            else if (!y)
+            if (!y)
                 return 1;
-            else if (*x == *y)
+            if (*x == *y)
                 return 0;
-            else if (*x < *y)
+            if (*x < *y)
                 return -1;
-            else
             return 1;
         }
         else
         {
             if (x == y)
                 return 0;
-            else if (x < y)
+            if (x < y)
                 return -1;
-            else
             return 1;
         }
     };

src/Access/KerberosInit.cpp

@@ -166,8 +166,7 @@ void KerberosInit::init(const String & keytab_file, const String & principal, co
         ret = krb5_get_init_creds_keytab(k5.ctx, &my_creds, k5.me, keytab, 0, nullptr, options);
         if (ret)
             throw Exception(ErrorCodes::KERBEROS_ERROR, "Error in getting initial credentials: {}", fmtError(ret));
-        else
-            LOG_TRACE(log,"Got initial credentials");
+        LOG_TRACE(log, "Got initial credentials");
     }
     else
     {

src/Access/LDAPAccessStorage.cpp

@@ -330,10 +330,7 @@ std::set<String> LDAPAccessStorage::mapExternalRolesNoLock(const LDAPClient::Sea
 
         for (const auto & external_role : external_role_set)
         {
-            if (
-                prefix.size() < external_role.size() &&
-                external_role.compare(0, prefix.size(), prefix) == 0
-            )
+            if (prefix.size() < external_role.size() && external_role.starts_with(prefix))
             {
                 role_names.emplace(external_role, prefix.size());
             }

src/Access/QuotaCache.cpp

@@ -62,7 +62,6 @@ String QuotaCache::QuotaInfo::calculateKey(const EnabledQuota & enabled, bool th
                     "Quota {} (for user {}) requires a client supplied key.",
                     quota->getName(),
                     params.user_name);
-            else
             return ""; // Authentication quota has no client key at time of authentication.
         }
         case QuotaKeyType::CLIENT_KEY_OR_USER_NAME:

src/Access/RolesOrUsersSet.cpp

@@ -80,15 +80,13 @@ void RolesOrUsersSet::init(const ASTRolesOrUsersSet & ast, const AccessControl *
                 return *id;
             return access_control->getID<Role>(name);
         }
-        else if (ast.allow_users)
+        if (ast.allow_users)
         {
             return access_control->getID<User>(name);
         }
-        else
-        {
+
         assert(ast.allow_roles);
         return access_control->getID<Role>(name);
-        }
     };
 
     if (!ast.names.empty() && !all)

src/Access/SettingsAuthResponseParser.cpp

@@ -28,7 +28,7 @@ SettingsAuthResponseParser::parse(const Poco::Net::HTTPResponse & response, std:
     try
     {
         Poco::Dynamic::Var json = parser.parse(*body_stream);
-        Poco::JSON::Object::Ptr obj = json.extract<Poco::JSON::Object::Ptr>();
+        const Poco::JSON::Object::Ptr & obj = json.extract<Poco::JSON::Object::Ptr>();
         Poco::JSON::Object::Ptr settings_obj = obj->getObject(settings_key);
 
         if (settings_obj)

src/Access/SettingsConstraints.cpp

@@ -54,7 +54,6 @@ SettingSourceRestrictions getSettingSourceRestrictions(std::string_view name)
     auto settingConstraintIter = SETTINGS_SOURCE_RESTRICTIONS.find(name);
     if (settingConstraintIter != SETTINGS_SOURCE_RESTRICTIONS.end())
         return settingConstraintIter->second;
-    else
     return SettingSourceRestrictions(); // allows everything
 }
 
@@ -310,7 +309,6 @@ bool SettingsConstraints::Checker::check(SettingChange & change,
     {
         if (reaction == THROW_ON_VIOLATION)
             throw Exception(explain, code);
-        else
         return false;
     }
 
@@ -335,7 +333,6 @@ bool SettingsConstraints::Checker::check(SettingChange & change,
     {
         if (reaction == THROW_ON_VIOLATION)
             throw Exception(ErrorCodes::SETTING_CONSTRAINT_VIOLATION, "Setting {} should not be changed", setting_name);
-        else
         return false;
     }
 
@@ -351,7 +348,6 @@ bool SettingsConstraints::Checker::check(SettingChange & change,
                 max_value,
                 min_value,
                 setting_name);
-        else
         return false;
     }
 
@@ -362,7 +358,6 @@ bool SettingsConstraints::Checker::check(SettingChange & change,
             throw Exception(ErrorCodes::SETTING_CONSTRAINT_VIOLATION, "Setting {} shouldn't be less than {}",
                 setting_name, applyVisitor(FieldVisitorToString(), min_value));
         }
-        else
         change.value = min_value;
     }
 
@@ -373,7 +368,6 @@ bool SettingsConstraints::Checker::check(SettingChange & change,
             throw Exception(ErrorCodes::SETTING_CONSTRAINT_VIOLATION, "Setting {} shouldn't be greater than {}",
                 setting_name, applyVisitor(FieldVisitorToString(), max_value));
         }
-        else
         change.value = max_value;
     }
 
@@ -381,7 +375,6 @@ bool SettingsConstraints::Checker::check(SettingChange & change,
     {
         if (reaction == THROW_ON_VIOLATION)
             throw Exception(ErrorCodes::READONLY, "Setting {} is not allowed to be set by {}", setting_name, toString(source));
-        else
         return false;
     }
 

src/Access/UsersConfigAccessStorage.cpp

@@ -649,7 +649,6 @@ namespace
                 {
                     if (users_without_row_policies_can_read_rows)
                         continue;
-                    else
                     filter = "1";
                 }
 

src/AggregateFunctions/AggregateFunctionAnyRespectNulls.cpp

@@ -157,13 +157,13 @@ public:
         d.status = static_cast<Data::Status>(k);
         if (d.status == Data::Status::NotSet)
             return;
-        else if (d.status == Data::Status::SetNull)
+        if (d.status == Data::Status::SetNull)
         {
             if (!returns_nullable_type)
                 throw Exception(ErrorCodes::INCORRECT_DATA, "Incorrect type (NULL) in non-nullable {}State", getName());
             return;
         }
-        else if (d.status == Data::Status::SetOther)
+        if (d.status == Data::Status::SetOther)
         {
             serialization->deserializeBinary(d.value, buf, {});
             return;

src/AggregateFunctions/AggregateFunctionDeltaSum.cpp

@@ -148,9 +148,8 @@ AggregateFunctionPtr createAggregateFunctionDeltaSum(
     if (isInteger(data_type) || isFloat(data_type))
         return AggregateFunctionPtr(createWithNumericType<AggregationFunctionDeltaSum>(
             *data_type, arguments, params));
-    else
-        throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Illegal type {} of argument for aggregate function {}",
-            arguments[0]->getName(), name);
+    throw Exception(
+        ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Illegal type {} of argument for aggregate function {}", arguments[0]->getName(), name);
 }
 }
 

src/AggregateFunctions/AggregateFunctionFactory.cpp

@@ -137,13 +137,12 @@ AggregateFunctionFactory::getAssociatedFunctionByNullsAction(const String & name
 {
     if (action == NullsAction::RESPECT_NULLS)
     {
-        if (auto it = respect_nulls.find(name); it == respect_nulls.end())
+        auto it = respect_nulls.find(name);
+        if (it == respect_nulls.end())
             throw Exception(ErrorCodes::NOT_IMPLEMENTED, "Function {} does not support RESPECT NULLS", name);
-        else if (auto associated_it = aggregate_functions.find(it->second); associated_it != aggregate_functions.end())
+        if (auto associated_it = aggregate_functions.find(it->second); associated_it != aggregate_functions.end())
             return {associated_it->second};
-        else
-            throw Exception(
-                ErrorCodes::LOGICAL_ERROR, "Unable to find the function {} (equivalent to '{} RESPECT NULLS')", it->second, name);
+        throw Exception(ErrorCodes::LOGICAL_ERROR, "Unable to find the function {} (equivalent to '{} RESPECT NULLS')", it->second, name);
     }
 
     if (action == NullsAction::IGNORE_NULLS)
@@ -152,7 +151,6 @@ AggregateFunctionFactory::getAssociatedFunctionByNullsAction(const String & name
         {
             if (auto associated_it = aggregate_functions.find(it->second); associated_it != aggregate_functions.end())
                 return {associated_it->second};
-            else
             throw Exception(
                 ErrorCodes::LOGICAL_ERROR, "Unable to find the function {} (equivalent to '{} IGNORE NULLS')", it->second, name);
         }
@@ -263,7 +261,6 @@ AggregateFunctionPtr AggregateFunctionFactory::getImpl(
     if (!hints.empty())
         throw Exception(ErrorCodes::UNKNOWN_AGGREGATE_FUNCTION,
                         "Unknown aggregate function {}{}. Maybe you meant: {}", name, extra_info, toString(hints));
-    else
     throw Exception(ErrorCodes::UNKNOWN_AGGREGATE_FUNCTION, "Unknown aggregate function {}{}", name, extra_info);
 }
 

src/AggregateFunctions/AggregateFunctionFlameGraph.cpp

@@ -328,8 +328,7 @@ struct AggregateFunctionFlameGraphData
             list = list->next;
             return entry;
         }
-        else
-        {
+
         Entry * parent = list;
         while (parent->next && parent->next->size != size)
             parent = parent->next;
@@ -343,7 +342,6 @@ struct AggregateFunctionFlameGraphData
 
         return nullptr;
     }
-    }
 
     void add(UInt64 ptr, Int64 size, const UInt64 * stack, size_t stack_size, Arena * arena)
     {

src/AggregateFunctions/AggregateFunctionGroupArray.cpp

@@ -90,7 +90,6 @@ struct GroupArraySamplerData
         /// With a large number of values, we will generate random numbers several times slower.
         if (lim <= static_cast<UInt64>(pcg32_fast::max()))
             return rng() % lim;
-        else
         return (static_cast<UInt64>(rng()) * (static_cast<UInt64>(pcg32::max()) + 1ULL) + static_cast<UInt64>(rng())) % lim;
     }
 
@@ -797,8 +796,8 @@ AggregateFunctionPtr createAggregateFunctionGroupArray(
             throw Exception(ErrorCodes::BAD_ARGUMENTS, "groupArrayLast make sense only with max_elems (groupArrayLast(max_elems)())");
         return createAggregateFunctionGroupArrayImpl<GroupArrayTrait</* Thas_limit= */ false, Tlast, /* Tsampler= */ Sampler::NONE>>(argument_types[0], parameters, max_elems, std::nullopt);
     }
-    else
-        return createAggregateFunctionGroupArrayImpl<GroupArrayTrait</* Thas_limit= */ true, Tlast, /* Tsampler= */ Sampler::NONE>>(argument_types[0], parameters, max_elems, std::nullopt);
+    return createAggregateFunctionGroupArrayImpl<GroupArrayTrait</* Thas_limit= */ true, Tlast, /* Tsampler= */ Sampler::NONE>>(
+        argument_types[0], parameters, max_elems, std::nullopt);
 }
 
 AggregateFunctionPtr createAggregateFunctionGroupArraySample(

src/AggregateFunctions/AggregateFunctionGroupArrayIntersect.cpp

@@ -381,23 +381,22 @@ IAggregateFunction * createWithExtraTypes(const DataTypePtr & argument_type, con
 {
     WhichDataType which(argument_type);
     if (which.idx == TypeIndex::Date) return new AggregateFunctionGroupArrayIntersectDate(argument_type, parameters);
-    else if (which.idx == TypeIndex::DateTime) return new AggregateFunctionGroupArrayIntersectDateTime(argument_type, parameters);
-    else if (which.idx == TypeIndex::Date32) return new AggregateFunctionGroupArrayIntersectDate32(argument_type, parameters);
-    else if (which.idx == TypeIndex::DateTime64)
+    if (which.idx == TypeIndex::DateTime)
+        return new AggregateFunctionGroupArrayIntersectDateTime(argument_type, parameters);
+    if (which.idx == TypeIndex::Date32)
+        return new AggregateFunctionGroupArrayIntersectDate32(argument_type, parameters);
+    if (which.idx == TypeIndex::DateTime64)
     {
         const auto * datetime64_type = dynamic_cast<const DataTypeDateTime64 *>(argument_type.get());
         const auto return_type = std::make_shared<DataTypeArray>(std::make_shared<DataTypeDateTime64>(datetime64_type->getScale()));
 
         return new AggregateFunctionGroupArrayIntersectGeneric<true>(argument_type, parameters, return_type);
     }
-    else
-    {
+
     /// Check that we can use plain version of AggregateFunctionGroupArrayIntersectGeneric
     if (argument_type->isValueUnambiguouslyRepresentedInContiguousMemoryRegion())
         return new AggregateFunctionGroupArrayIntersectGeneric<true>(argument_type, parameters);
-        else
     return new AggregateFunctionGroupArrayIntersectGeneric<false>(argument_type, parameters);
-    }
 }
 
 inline AggregateFunctionPtr createAggregateFunctionGroupArrayIntersectImpl(const std::string & name, const DataTypePtr & argument_type, const Array & parameters)

src/AggregateFunctions/AggregateFunctionGroupArrayMoving.cpp

@@ -65,7 +65,6 @@ struct MovingSumData : public MovingData<T>
     {
         if (idx < window_size)
             return this->value[idx];
-        else
         return this->value[idx] - this->value[idx - window_size];
     }
 };
@@ -79,7 +78,6 @@ struct MovingAvgData : public MovingData<T>
     {
         if (idx < window_size)
             return this->value[idx] / T(window_size);
-        else
         return (this->value[idx] - this->value[idx - window_size]) / T(window_size);
     }
 };
@@ -285,16 +283,12 @@ AggregateFunctionPtr createAggregateFunctionMoving(
     {
         if (isDecimal(argument_type))
             return createAggregateFunctionMovingImpl<Function, std::false_type, std::true_type>(name, argument_type);
-        else
         return createAggregateFunctionMovingImpl<Function, std::false_type, std::false_type>(name, argument_type);
     }
-    else
-    {
+
     if (isDecimal(argument_type))
         return createAggregateFunctionMovingImpl<Function, std::true_type, std::true_type>(name, argument_type, max_elems);
-        else
     return createAggregateFunctionMovingImpl<Function, std::true_type, std::false_type>(name, argument_type, max_elems);
-    }
 }
 
 }

src/AggregateFunctions/AggregateFunctionGroupArraySorted.cpp

@@ -391,21 +391,20 @@ AggregateFunctionPtr createAggregateFunctionGroupArray(
     {
         throw Exception(ErrorCodes::BAD_ARGUMENTS, "Parameter for aggregate function {} should have limit argument", name);
     }
-    else if (parameters.size() == 1)
+    if (parameters.size() == 1)
     {
         auto type = parameters[0].getType();
         if (type != Field::Types::Int64 && type != Field::Types::UInt64)
             throw Exception(ErrorCodes::BAD_ARGUMENTS, "Parameter for aggregate function {} should be positive number", name);
 
-        if ((type == Field::Types::Int64 && parameters[0].safeGet<Int64>() < 0) ||
-            (type == Field::Types::UInt64 && parameters[0].safeGet<UInt64>() == 0))
+        if ((type == Field::Types::Int64 && parameters[0].safeGet<Int64>() < 0)
+            || (type == Field::Types::UInt64 && parameters[0].safeGet<UInt64>() == 0))
             throw Exception(ErrorCodes::BAD_ARGUMENTS, "Parameter for aggregate function {} should be positive number", name);
 
         max_elems = parameters[0].safeGet<UInt64>();
     }
     else
-        throw Exception(ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH,
-            "Function {} does not support this number of arguments", name);
+        throw Exception(ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH, "Function {} does not support this number of arguments", name);
 
     if (max_elems > group_array_sorted_sort_strategy_max_elements_threshold)
         return createAggregateFunctionGroupArraySortedImpl<GroupArraySortedSort>(argument_types[0], parameters, max_elems);

src/AggregateFunctions/AggregateFunctionGroupBitmap.cpp

@@ -133,7 +133,6 @@ public:
     {
         if (revision >= STATE_VERSION_1_MIN_REVISION)
             return 1;
-        else
         return 0;
     }
 

src/AggregateFunctions/AggregateFunctionGroupBitmapData.h

@@ -88,7 +88,6 @@ public:
     {
         if (isSmall())
             return small.size();
-        else
         return roaring_bitmap->cardinality();
     }
 
@@ -454,7 +453,6 @@ public:
 
         if (isSmall())
             return small.find(static_cast<T>(x)) != small.end();
-        else
         return roaring_bitmap->contains(static_cast<Value>(x));
     }
 
@@ -554,8 +552,7 @@ public:
                 r1.add(elem);
             return answer.size();
         }
-        else
-        {
+
         UInt64 count = 0;
         for (auto it = roaring_bitmap->begin(); it != roaring_bitmap->end(); ++it)
         {
@@ -572,7 +569,6 @@ public:
         }
         return count;
     }
-    }
 
     UInt64 rb_offset_limit(UInt64 offset, UInt64 limit, RoaringBitmapWithSmallSet & r1) const /// NOLINT
     {
@@ -591,19 +587,17 @@ public:
                 r1.add(it->getValue());
             return count;
         }
-        else
-        {
+
         UInt64 count = 0;
         UInt64 offset_count = 0;
         auto it = roaring_bitmap->begin();
-            for (;it != roaring_bitmap->end() && offset_count < offset; ++it)
+        for (; it != roaring_bitmap->end() && offset_count < offset; ++it)
             ++offset_count;
 
-            for (;it != roaring_bitmap->end() && count < limit; ++it, ++count)
+        for (; it != roaring_bitmap->end() && count < limit; ++it, ++count)
             r1.add(*it);
         return count;
     }
-    }
 
     UInt64 rb_min() const /// NOLINT
     {
@@ -620,7 +614,6 @@ public:
             }
             return min_val;
         }
-        else
         return roaring_bitmap->minimum();
     }
 
@@ -639,7 +632,6 @@ public:
             }
             return max_val;
         }
-        else
         return roaring_bitmap->maximum();
     }
 

src/AggregateFunctions/AggregateFunctionGroupConcat.cpp

@@ -275,7 +275,6 @@ AggregateFunctionPtr createAggregateFunctionGroupConcat(
 
     if (has_limit)
         return std::make_shared<GroupConcatImpl</* has_limit= */ true>>(argument_types[0], parameters, limit, delimiter);
-    else
     return std::make_shared<GroupConcatImpl</* has_limit= */ false>>(argument_types[0], parameters, limit, delimiter);
 }
 

src/AggregateFunctions/AggregateFunctionGroupUniqArray.cpp

@@ -276,16 +276,15 @@ IAggregateFunction * createWithExtraTypes(const DataTypePtr & argument_type, TAr
 {
     WhichDataType which(argument_type);
     if (which.idx == TypeIndex::Date) return new AggregateFunctionGroupUniqArrayDate<HasLimit>(argument_type, args...);
-    else if (which.idx == TypeIndex::DateTime) return new AggregateFunctionGroupUniqArrayDateTime<HasLimit>(argument_type, args...);
-    else if (which.idx == TypeIndex::IPv4) return new AggregateFunctionGroupUniqArrayIPv4<HasLimit>(argument_type, args...);
-    else
-    {
+    if (which.idx == TypeIndex::DateTime)
+        return new AggregateFunctionGroupUniqArrayDateTime<HasLimit>(argument_type, args...);
+    if (which.idx == TypeIndex::IPv4)
+        return new AggregateFunctionGroupUniqArrayIPv4<HasLimit>(argument_type, args...);
+
     /// Check that we can use plain version of AggregateFunctionGroupUniqArrayGeneric
     if (argument_type->isValueUnambiguouslyRepresentedInContiguousMemoryRegion())
         return new AggregateFunctionGroupUniqArrayGeneric<true, HasLimit>(argument_type, args...);
-        else
     return new AggregateFunctionGroupUniqArrayGeneric<false, HasLimit>(argument_type, args...);
-    }
 }
 
 template <typename HasLimit, typename ... TArgs>
@@ -336,7 +335,6 @@ AggregateFunctionPtr createAggregateFunctionGroupUniqArray(
 
     if (!limit_size)
         return createAggregateFunctionGroupUniqArrayImpl<std::false_type>(name, argument_types[0], parameters);
-    else
     return createAggregateFunctionGroupUniqArrayImpl<std::true_type>(name, argument_types[0], parameters, max_elems);
 }
 

src/AggregateFunctions/AggregateFunctionMaxIntersections.cpp

@@ -87,7 +87,6 @@ public:
     {
         if (kind_ == AggregateFunctionIntersectionsKind::Count)
             return std::make_shared<DataTypeUInt64>();
-        else
         return std::make_shared<DataTypeNumber<PointType>>();
     }
 

src/AggregateFunctions/AggregateFunctionQuantileGK.cpp

@@ -138,7 +138,9 @@ public:
     {
         if (other.count == 0)
             return;
-        else if (count == 0)
+
+        /// NOLINTBEGIN(readability-else-after-return)
+        if (count == 0)
         {
             compress_threshold = other.compress_threshold;
             relative_error = other.relative_error;
@@ -237,6 +239,7 @@ public:
             doCompress(2 * merged_relative_error * merged_count);
             compressed = true;
         }
+        /// NOLINTEND(readability-else-after-return)
     }
 
     void write(WriteBuffer & buf) const
@@ -292,13 +295,11 @@ private:
             Int64 max_rank = min_rank + curr_sample.delta;
             if (max_rank - target_error <= rank && rank <= min_rank + target_error)
                 return {i, min_rank, curr_sample.value};
-            else
-            {
+
             ++i;
             curr_sample = sampled[i];
             min_rank += curr_sample.g;
         }
-        }
         return {sampled.size() - 1, 0, sampled.back().value};
     }
 

src/AggregateFunctions/AggregateFunctionSequenceMatch.cpp

@@ -747,7 +747,7 @@ AggregateFunctionPtr createAggregateFunctionSequenceBase(
     WhichDataType which(argument_types.front().get());
     if (which.isDateTime())
         return std::make_shared<AggregateFunction<DataTypeDateTime::FieldType, Data<DataTypeDateTime::FieldType>>>(argument_types, params, pattern);
-    else if (which.isDate())
+    if (which.isDate())
         return std::make_shared<AggregateFunction<DataTypeDate::FieldType, Data<DataTypeDate::FieldType>>>(argument_types, params, pattern);
 
     throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,

src/AggregateFunctions/AggregateFunctionStatistics.cpp

@@ -124,7 +124,6 @@ private:
     {
         if (count < 2)
             return std::numeric_limits<Float64>::infinity();
-        else
         return m2 / (count - 1);
     }
 
@@ -137,9 +136,8 @@ private:
     {
         if (count == 0)
             return std::numeric_limits<Float64>::infinity();
-        else if (count == 1)
+        if (count == 1)
             return 0.0;
-        else
         return m2 / count;
     }
 
@@ -363,7 +361,6 @@ private:
     {
         if (count < 2)
             return std::numeric_limits<Float64>::infinity();
-        else
         return co_moment / (count - 1);
     }
 
@@ -371,9 +368,8 @@ private:
     {
         if (count == 0)
             return std::numeric_limits<Float64>::infinity();
-        else if (count == 1)
+        if (count == 1)
             return 0.0;
-        else
         return co_moment / count;
     }
 
@@ -381,7 +377,6 @@ private:
     {
         if (count < 2)
             return std::numeric_limits<Float64>::infinity();
-        else
         return co_moment / sqrt(left_m2 * right_m2);
     }
 

src/AggregateFunctions/AggregateFunctionSumMap.cpp

@@ -112,7 +112,6 @@ public:
     {
         if (revision >= STATE_VERSION_1_MIN_REVISION)
             return 1;
-        else
         return 0;
     }
 
@@ -764,7 +763,6 @@ void registerAggregateFunctionSumMap(AggregateFunctionFactory & factory)
         auto [keys_type, values_types, tuple_argument] = parseArguments(name, arguments);
         if (tuple_argument)
             return std::make_shared<AggregateFunctionSumMap<false, true>>(keys_type, values_types, arguments, params);
-        else
         return std::make_shared<AggregateFunctionSumMap<false, false>>(keys_type, values_types, arguments, params);
     });
 
@@ -773,7 +771,6 @@ void registerAggregateFunctionSumMap(AggregateFunctionFactory & factory)
         auto [keys_type, values_types, tuple_argument] = parseArguments(name, arguments);
         if (tuple_argument)
             return std::make_shared<AggregateFunctionMinMap<true>>(keys_type, values_types, arguments, params);
-        else
         return std::make_shared<AggregateFunctionMinMap<false>>(keys_type, values_types, arguments, params);
     });
 
@@ -782,7 +779,6 @@ void registerAggregateFunctionSumMap(AggregateFunctionFactory & factory)
         auto [keys_type, values_types, tuple_argument] = parseArguments(name, arguments);
         if (tuple_argument)
             return std::make_shared<AggregateFunctionMaxMap<true>>(keys_type, values_types, arguments, params);
-        else
         return std::make_shared<AggregateFunctionMaxMap<false>>(keys_type, values_types, arguments, params);
     });
 
@@ -793,7 +789,6 @@ void registerAggregateFunctionSumMap(AggregateFunctionFactory & factory)
         auto [keys_type, values_types, tuple_argument] = parseArguments(name, arguments);
         if (tuple_argument)
             return std::make_shared<AggregateFunctionSumMap<true, true>>(keys_type, values_types, arguments, params);
-        else
         return std::make_shared<AggregateFunctionSumMap<true, false>>(keys_type, values_types, arguments, params);
     });
 
@@ -802,7 +797,6 @@ void registerAggregateFunctionSumMap(AggregateFunctionFactory & factory)
         auto [keys_type, values_types, tuple_argument] = parseArguments(name, arguments);
         if (tuple_argument)
             return std::make_shared<AggregateFunctionSumMapFiltered<false, true>>(keys_type, values_types, arguments, params);
-        else
         return std::make_shared<AggregateFunctionSumMapFiltered<false, false>>(keys_type, values_types, arguments, params);
     });
 
@@ -811,7 +805,6 @@ void registerAggregateFunctionSumMap(AggregateFunctionFactory & factory)
         auto [keys_type, values_types, tuple_argument] = parseArguments(name, arguments);
         if (tuple_argument)
             return std::make_shared<AggregateFunctionSumMapFiltered<true, true>>(keys_type, values_types, arguments, params);
-        else
         return std::make_shared<AggregateFunctionSumMapFiltered<true, false>>(keys_type, values_types, arguments, params);
     });
 }

src/AggregateFunctions/AggregateFunctionTTest.h

@@ -96,25 +96,18 @@ public:
                 std::move(names)
             );
         }
-        else
-        {
-            DataTypes types
-            {
+
+        DataTypes types{
             std::make_shared<DataTypeNumber<Float64>>(),
             std::make_shared<DataTypeNumber<Float64>>(),
         };
 
-            Strings names
-            {
+        Strings names{
             "t_statistic",
             "p_value",
         };
 
-            return std::make_shared<DataTypeTuple>(
-                std::move(types),
-                std::move(names)
-            );
-        }
+        return std::make_shared<DataTypeTuple>(std::move(types), std::move(names));
     }
 
     bool allocatesMemoryInArena() const override { return false; }

src/AggregateFunctions/AggregateFunctionTopK.cpp

@@ -79,7 +79,6 @@ public:
     {
         if (is_approx_top_k)
             return  is_weighted ? "approx_top_sum" : "approx_top_k";
-        else
         return is_weighted ? "topKWeighted" : "topK";
     }
 
@@ -106,7 +105,6 @@ public:
                 std::move(names)
             ));
         }
-        else
         return std::make_shared<DataTypeArray>(argument_types_[0]);
     }
 
@@ -226,7 +224,6 @@ public:
     {
         if (is_approx_top_k)
             return  is_weighted ? "approx_top_sum" : "approx_top_k";
-        else
         return is_weighted ? "topKWeighted" : "topK";
     }
 
@@ -253,10 +250,8 @@ public:
                 std::move(names)
             ));
 
-        } else
-        {
-            return std::make_shared<DataTypeArray>(argument_types_[0]);
         }
+        return std::make_shared<DataTypeArray>(argument_types_[0]);
     }
 
     bool allocatesMemoryInArena() const override
@@ -440,8 +435,8 @@ IAggregateFunction * createWithExtraTypes(const DataTypes & argument_types, UInt
     /// Check that we can use plain version of AggregateFunctionTopKGeneric
     if (argument_types[0]->isValueUnambiguouslyRepresentedInContiguousMemoryRegion())
         return new AggregateFunctionTopKGeneric<true, is_weighted>(threshold, reserved, include_counts, is_approx_top_k, argument_types, params);
-    else
-        return new AggregateFunctionTopKGeneric<false, is_weighted>(threshold, reserved, include_counts, is_approx_top_k, argument_types, params);
+    return new AggregateFunctionTopKGeneric<false, is_weighted>(
+        threshold, reserved, include_counts, is_approx_top_k, argument_types, params);
 }
 
 

src/AggregateFunctions/AggregateFunctionUniq.cpp

@@ -54,25 +54,24 @@ createAggregateFunctionUniq(const std::string & name, const DataTypes & argument
         WhichDataType which(argument_type);
         if (res)
             return res;
-        else if (which.isDate())
+        if (which.isDate())
             return std::make_shared<AggregateFunctionUniq<DataTypeDate::FieldType, Data>>(argument_types);
-        else if (which.isDate32())
+        if (which.isDate32())
             return std::make_shared<AggregateFunctionUniq<DataTypeDate32::FieldType, Data>>(argument_types);
-        else if (which.isDateTime())
+        if (which.isDateTime())
             return std::make_shared<AggregateFunctionUniq<DataTypeDateTime::FieldType, Data>>(argument_types);
-        else if (which.isStringOrFixedString())
+        if (which.isStringOrFixedString())
             return std::make_shared<AggregateFunctionUniq<String, Data>>(argument_types);
-        else if (which.isUUID())
+        if (which.isUUID())
             return std::make_shared<AggregateFunctionUniq<DataTypeUUID::FieldType, Data>>(argument_types);
-        else if (which.isIPv4())
+        if (which.isIPv4())
             return std::make_shared<AggregateFunctionUniq<DataTypeIPv4::FieldType, Data>>(argument_types);
-        else if (which.isIPv6())
+        if (which.isIPv6())
             return std::make_shared<AggregateFunctionUniq<DataTypeIPv6::FieldType, Data>>(argument_types);
-        else if (which.isTuple())
+        if (which.isTuple())
         {
             if (use_exact_hash_function)
                 return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic<true, true>>>(argument_types);
-            else
             return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic<false, true>>>(argument_types);
         }
     }
@@ -80,7 +79,6 @@ createAggregateFunctionUniq(const std::string & name, const DataTypes & argument
     /// "Variadic" method also works as a fallback generic case for single argument.
     if (use_exact_hash_function)
         return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic<true, false>>>(argument_types);
-    else
     return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic<false, false>>>(argument_types);
 }
 
@@ -107,33 +105,45 @@ createAggregateFunctionUniq(const std::string & name, const DataTypes & argument
         WhichDataType which(argument_type);
         if (res)
             return res;
-        else if (which.isDate())
-            return std::make_shared<AggregateFunctionUniq<DataTypeDate::FieldType, Data<DataTypeDate::FieldType, is_able_to_parallelize_merge>>>(argument_types);
-        else if (which.isDate32())
-            return std::make_shared<AggregateFunctionUniq<DataTypeDate32::FieldType, Data<DataTypeDate32::FieldType, is_able_to_parallelize_merge>>>(argument_types);
-        else if (which.isDateTime())
-            return std::make_shared<AggregateFunctionUniq<DataTypeDateTime::FieldType, Data<DataTypeDateTime::FieldType, is_able_to_parallelize_merge>>>(argument_types);
-        else if (which.isStringOrFixedString())
+        if (which.isDate())
+            return std::make_shared<
+                AggregateFunctionUniq<DataTypeDate::FieldType, Data<DataTypeDate::FieldType, is_able_to_parallelize_merge>>>(
+                argument_types);
+        if (which.isDate32())
+            return std::make_shared<
+                AggregateFunctionUniq<DataTypeDate32::FieldType, Data<DataTypeDate32::FieldType, is_able_to_parallelize_merge>>>(
+                argument_types);
+        if (which.isDateTime())
+            return std::make_shared<
+                AggregateFunctionUniq<DataTypeDateTime::FieldType, Data<DataTypeDateTime::FieldType, is_able_to_parallelize_merge>>>(
+                argument_types);
+        if (which.isStringOrFixedString())
             return std::make_shared<AggregateFunctionUniq<String, Data<String, is_able_to_parallelize_merge>>>(argument_types);
-        else if (which.isUUID())
-            return std::make_shared<AggregateFunctionUniq<DataTypeUUID::FieldType, Data<DataTypeUUID::FieldType, is_able_to_parallelize_merge>>>(argument_types);
-        else if (which.isIPv4())
-            return std::make_shared<AggregateFunctionUniq<DataTypeIPv4::FieldType, Data<DataTypeIPv4::FieldType, is_able_to_parallelize_merge>>>(argument_types);
-        else if (which.isIPv6())
-            return std::make_shared<AggregateFunctionUniq<DataTypeIPv6::FieldType, Data<DataTypeIPv6::FieldType, is_able_to_parallelize_merge>>>(argument_types);
-        else if (which.isTuple())
+        if (which.isUUID())
+            return std::make_shared<
+                AggregateFunctionUniq<DataTypeUUID::FieldType, Data<DataTypeUUID::FieldType, is_able_to_parallelize_merge>>>(
+                argument_types);
+        if (which.isIPv4())
+            return std::make_shared<
+                AggregateFunctionUniq<DataTypeIPv4::FieldType, Data<DataTypeIPv4::FieldType, is_able_to_parallelize_merge>>>(
+                argument_types);
+        if (which.isIPv6())
+            return std::make_shared<
+                AggregateFunctionUniq<DataTypeIPv6::FieldType, Data<DataTypeIPv6::FieldType, is_able_to_parallelize_merge>>>(
+                argument_types);
+        if (which.isTuple())
         {
             if (use_exact_hash_function)
-                return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic<true, true, is_able_to_parallelize_merge>>>(argument_types);
-            else
-                return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic<false, true, is_able_to_parallelize_merge>>>(argument_types);
+                return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic<true, true, is_able_to_parallelize_merge>>>(
+                    argument_types);
+            return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic<false, true, is_able_to_parallelize_merge>>>(
+                argument_types);
         }
     }
 
     /// "Variadic" method also works as a fallback generic case for single argument.
     if (use_exact_hash_function)
         return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic<true, false, is_able_to_parallelize_merge>>>(argument_types);
-    else
     return std::make_shared<AggregateFunctionUniqVariadic<DataForVariadic<false, false, is_able_to_parallelize_merge>>>(argument_types);
 }
 
@@ -155,9 +165,11 @@ void registerAggregateFunctionsUniq(AggregateFunctionFactory & factory)
         if (settings && (*settings)[Setting::max_threads] > 1)
             return createAggregateFunctionUniq<
                 true, AggregateFunctionUniqExactData, AggregateFunctionUniqExactDataForVariadic, true /* is_able_to_parallelize_merge */>(name, argument_types, params, settings);
-        else
         return createAggregateFunctionUniq<
-                true, AggregateFunctionUniqExactData, AggregateFunctionUniqExactDataForVariadic, false /* is_able_to_parallelize_merge */>(name, argument_types, params, settings);
+            true,
+            AggregateFunctionUniqExactData,
+            AggregateFunctionUniqExactDataForVariadic,
+            false /* is_able_to_parallelize_merge */>(name, argument_types, params, settings);
     };
     factory.registerFunction("uniqExact", {assign_bool_param, properties});
 

src/AggregateFunctions/AggregateFunctionUniqCombined.h

@@ -235,33 +235,39 @@ AggregateFunctionPtr createAggregateFunctionWithK(const DataTypes & argument_typ
         WhichDataType which(argument_type);
         if (res)
             return res;
-        else if (which.isDate())
-            return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunction<DataTypeDate::FieldType>>(argument_types, params);
-        else if (which.isDate32())
-            return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunction<DataTypeDate32::FieldType>>(argument_types, params);
-        else if (which.isDateTime())
-            return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunction<DataTypeDateTime::FieldType>>(argument_types, params);
-        else if (which.isStringOrFixedString())
+        if (which.isDate())
+            return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunction<DataTypeDate::FieldType>>(
+                argument_types, params);
+        if (which.isDate32())
+            return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunction<DataTypeDate32::FieldType>>(
+                argument_types, params);
+        if (which.isDateTime())
+            return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunction<DataTypeDateTime::FieldType>>(
+                argument_types, params);
+        if (which.isStringOrFixedString())
             return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunction<String>>(argument_types, params);
-        else if (which.isUUID())
-            return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunction<DataTypeUUID::FieldType>>(argument_types, params);
-        else if (which.isIPv4())
-            return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunction<DataTypeIPv4::FieldType>>(argument_types, params);
-        else if (which.isIPv6())
-            return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunction<DataTypeIPv6::FieldType>>(argument_types, params);
-        else if (which.isTuple())
+        if (which.isUUID())
+            return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunction<DataTypeUUID::FieldType>>(
+                argument_types, params);
+        if (which.isIPv4())
+            return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunction<DataTypeIPv4::FieldType>>(
+                argument_types, params);
+        if (which.isIPv6())
+            return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunction<DataTypeIPv6::FieldType>>(
+                argument_types, params);
+        if (which.isTuple())
         {
             if (use_exact_hash_function)
-                return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunctionVariadic<true, true>>(argument_types, params);
-            else
-                return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunctionVariadic<false, true>>(argument_types, params);
+                return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunctionVariadic<true, true>>(
+                    argument_types, params);
+            return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunctionVariadic<false, true>>(
+                argument_types, params);
         }
     }
 
     /// "Variadic" method also works as a fallback generic case for a single argument.
     if (use_exact_hash_function)
         return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunctionVariadic<true, false>>(argument_types, params);
-    else
     return std::make_shared<typename WithK<K, HashValueType>::template AggregateFunctionVariadic<false, false>>(argument_types, params);
 }
 
@@ -270,7 +276,6 @@ AggregateFunctionPtr createAggregateFunctionWithHashType(bool use_64_bit_hash, c
 {
     if (use_64_bit_hash)
         return createAggregateFunctionWithK<K, UInt64>(argument_types, params);
-    else
     return createAggregateFunctionWithK<K, UInt32>(argument_types, params);
 }
 

src/AggregateFunctions/AggregateFunctionUniqUpTo.cpp

@@ -324,21 +324,20 @@ AggregateFunctionPtr createAggregateFunctionUniqUpTo(const std::string & name, c
         WhichDataType which(argument_type);
         if (res)
             return res;
-        else if (which.isDate())
+        if (which.isDate())
             return std::make_shared<AggregateFunctionUniqUpTo<DataTypeDate::FieldType>>(threshold, argument_types, params);
-        else if (which.isDate32())
+        if (which.isDate32())
             return std::make_shared<AggregateFunctionUniqUpTo<DataTypeDate32::FieldType>>(threshold, argument_types, params);
-        else if (which.isDateTime())
+        if (which.isDateTime())
             return std::make_shared<AggregateFunctionUniqUpTo<DataTypeDateTime::FieldType>>(threshold, argument_types, params);
-        else if (which.isStringOrFixedString())
+        if (which.isStringOrFixedString())
             return std::make_shared<AggregateFunctionUniqUpTo<String>>(threshold, argument_types, params);
-        else if (which.isUUID())
+        if (which.isUUID())
             return std::make_shared<AggregateFunctionUniqUpTo<DataTypeUUID::FieldType>>(threshold, argument_types, params);
-        else if (which.isTuple())
+        if (which.isTuple())
         {
             if (use_exact_hash_function)
                 return std::make_shared<AggregateFunctionUniqUpToVariadic<true, true>>(argument_types, params, threshold);
-            else
             return std::make_shared<AggregateFunctionUniqUpToVariadic<false, true>>(argument_types, params, threshold);
         }
     }
@@ -346,7 +345,6 @@ AggregateFunctionPtr createAggregateFunctionUniqUpTo(const std::string & name, c
     /// "Variadic" method also works as a fallback generic case for single argument.
     if (use_exact_hash_function)
         return std::make_shared<AggregateFunctionUniqUpToVariadic<true, false>>(argument_types, params, threshold);
-    else
     return std::make_shared<AggregateFunctionUniqUpToVariadic<false, false>>(argument_types, params, threshold);
 }
 

src/AggregateFunctions/AggregateFunctionWindowFunnel.cpp

@@ -180,10 +180,9 @@ private:
             {
                 if (first_event)
                     break;
-                else
                 continue;
             }
-            else if (event_idx == 0)
+            if (event_idx == 0)
             {
                 events_timestamp[0] = std::make_pair(timestamp, timestamp);
                 first_event = true;
@@ -326,10 +325,11 @@ createAggregateFunctionWindowFunnel(const std::string & name, const DataTypes &
     WhichDataType which(arguments.front().get());
     if (res)
         return res;
-    else if (which.isDate())
+    if (which.isDate())
         return std::make_shared<AggregateFunctionWindowFunnel<DataTypeDate::FieldType, Data<DataTypeDate::FieldType>>>(arguments, params);
-    else if (which.isDateTime())
-        return std::make_shared<AggregateFunctionWindowFunnel<DataTypeDateTime::FieldType, Data<DataTypeDateTime::FieldType>>>(arguments, params);
+    if (which.isDateTime())
+        return std::make_shared<AggregateFunctionWindowFunnel<DataTypeDateTime::FieldType, Data<DataTypeDateTime::FieldType>>>(
+            arguments, params);
 
     throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT,
                     "Illegal type {} of first argument of aggregate function {}, must "

src/AggregateFunctions/Combinators/AggregateFunctionDistinct.cpp

@@ -50,10 +50,8 @@ public:
                 return std::make_shared<
                     AggregateFunctionDistinct<
                         AggregateFunctionDistinctSingleGenericData<true>>>(nested_function, arguments, params);
-            else
-                return std::make_shared<
-                    AggregateFunctionDistinct<
-                        AggregateFunctionDistinctSingleGenericData<false>>>(nested_function, arguments, params);
+            return std::make_shared<AggregateFunctionDistinct<AggregateFunctionDistinctSingleGenericData<false>>>(
+                nested_function, arguments, params);
         }
 
         return std::make_shared<AggregateFunctionDistinct<AggregateFunctionDistinctMultipleGenericData>>(nested_function, arguments, params);

src/AggregateFunctions/Combinators/AggregateFunctionIf.cpp

@@ -473,28 +473,20 @@ AggregateFunctionPtr AggregateFunctionIf::getOwnNullAdapter(
         {
             return std::make_shared<AggregateFunctionIfNullUnary<true, true>>(nested_function->getName(), nested_func, arguments, params);
         }
-        else
-        {
+
         if (need_to_serialize_flag)
             return std::make_shared<AggregateFunctionIfNullUnary<false, true>>(nested_function->getName(), nested_func, arguments, params);
-            else
         return std::make_shared<AggregateFunctionIfNullUnary<false, false>>(nested_function->getName(), nested_func, arguments, params);
     }
-    }
-    else
-    {
+
     if (return_type_is_nullable)
     {
         return std::make_shared<AggregateFunctionIfNullVariadic<true, true>>(nested_function, arguments, params);
     }
-        else
-        {
+
     if (need_to_serialize_flag)
         return std::make_shared<AggregateFunctionIfNullVariadic<false, true>>(nested_function, arguments, params);
-            else
     return std::make_shared<AggregateFunctionIfNullVariadic<false, false>>(nested_function, arguments, params);
-        }
-    }
 }
 
 void registerAggregateFunctionCombinatorIf(AggregateFunctionCombinatorFactory & factory)

src/AggregateFunctions/Combinators/AggregateFunctionMap.cpp

@@ -450,9 +450,8 @@ public:
                 auto action = NullsAction::EMPTY;
                 return aggr_func_factory.get(nested_func_name + "MappedArrays", action, arguments, params, out_properties);
             }
-            else
-                throw Exception(ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Aggregation '{}Map' is not implemented for mapped arrays",
-                                 nested_func_name);
+            throw Exception(
+                ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT, "Aggregation '{}Map' is not implemented for mapped arrays", nested_func_name);
         }
     }
 };

src/AggregateFunctions/Combinators/AggregateFunctionNull.cpp

@@ -112,7 +112,6 @@ public:
               */
             if (properties.returns_default_when_only_null)
                 return std::make_shared<AggregateFunctionNothingUInt64>(arguments, params);
-            else
             return std::make_shared<AggregateFunctionNothingNull>(arguments, params);
         }
 
@@ -137,22 +136,17 @@ public:
             {
                 return std::make_shared<AggregateFunctionNullUnary<true, true>>(nested_function, arguments, params);
             }
-            else
-            {
+
             if (serialize_flag)
                 return std::make_shared<AggregateFunctionNullUnary<false, true>>(nested_function, arguments, params);
-                else
             return std::make_shared<AggregateFunctionNullUnary<false, false>>(nested_function, arguments, params);
         }
-        }
-        else
-        {
+
         if (return_type_is_nullable)
         {
             return std::make_shared<AggregateFunctionNullVariadic<true, true>>(nested_function, arguments, params);
         }
-            else
-            {
+
         return std::make_shared<AggregateFunctionNullVariadic<false, true>>(nested_function, arguments, params);
 #if 0
                 if (serialize_flag)
@@ -165,8 +159,6 @@ public:
             }
 #endif
     }
-        }
-    }
 };
 
 }

src/AggregateFunctions/Combinators/AggregateFunctionOrFill.cpp

@@ -37,7 +37,6 @@ public:
     {
         if (kind == Kind::OrNull)
             return std::make_shared<AggregateFunctionOrFill<true>>(nested_function, arguments, params);
-        else
         return std::make_shared<AggregateFunctionOrFill<false>>(nested_function, arguments, params);
     }
 };

src/AggregateFunctions/DDSketch.h

@@ -120,12 +120,10 @@ public:
                 this->merge(new_sketch);
                 return;
             }
-            else
-            {
+
             DDSketchDenseLogarithmic new_sketch = changeMapping(other.mapping->getGamma());
             copy(new_sketch);
         }
-        }
 
         // If the other sketch is empty, do nothing
         if (other.count == 0)

src/AggregateFunctions/IAggregateFunction.h

@@ -694,7 +694,7 @@ class IAggregateFunctionDataHelper : public IAggregateFunctionHelper<Derived>
 protected:
     using Data = T;
 
-    static Data & data(AggregateDataPtr __restrict place) { return *reinterpret_cast<Data *>(place); }
+    static Data & data(const AggregateDataPtr __restrict place) { return *reinterpret_cast<Data *>(place); }
     static const Data & data(ConstAggregateDataPtr __restrict place) { return *reinterpret_cast<const Data *>(place); }
 
 public:

src/AggregateFunctions/QuantileExact.h

@@ -146,7 +146,7 @@ struct QuantileExactExclusive : public QuantileExact<Value>
 
             if (n >= array.size())
                 return static_cast<Float64>(*std::max_element(array.begin(), array.end()));
-            else if (n < 1)
+            if (n < 1)
                 return static_cast<Float64>(*std::min_element(array.begin(), array.end()));
 
             ::nth_element(array.begin(), array.begin() + n - 1, array.end());
@@ -211,7 +211,7 @@ struct QuantileExactInclusive : public QuantileExact<Value>
 
             if (n >= array.size())
                 return static_cast<Float64>(*std::max_element(array.begin(), array.end()));
-            else if (n < 1)
+            if (n < 1)
                 return static_cast<Float64>(*std::min_element(array.begin(), array.end()));
             ::nth_element(array.begin(), array.begin() + n - 1, array.end());
             auto * nth_elem = std::min_element(array.begin() + n, array.end());

src/AggregateFunctions/QuantileTDigest.h

@@ -416,15 +416,10 @@ public:
 
                 if (x <= left)
                     return checkOverflow<ResultType>(prev_mean);
-                else if (x >= right)
+                if (x >= right)
                     return checkOverflow<ResultType>(c.mean);
-                else
-                    return checkOverflow<ResultType>(interpolate(
-                        static_cast<Value>(x),
-                        static_cast<Value>(left),
-                        prev_mean,
-                        static_cast<Value>(right),
-                        c.mean));
+                return checkOverflow<ResultType>(
+                    interpolate(static_cast<Value>(x), static_cast<Value>(left), prev_mean, static_cast<Value>(right), c.mean));
             }
 
             sum += c.count;

src/AggregateFunctions/QuantileTiming.h

@@ -736,15 +736,13 @@ public:
             tiny.prepare();
             return tiny.get(level);
         }
-        else if (kind == Kind::Medium)
+        if (kind == Kind::Medium)
         {
             return medium.get(level);
         }
-        else
-        {
+
         return large->get(level);
     }
-    }
 
     /// Get the size values of the quantiles of the `levels` levels. Record `size` results starting with `result` address.
     template <typename ResultType>

src/AggregateFunctions/ReservoirSampler.h

@@ -260,7 +260,6 @@ private:
         /// With a large number of values, we will generate random numbers several times slower.
         if (limit <= static_cast<UInt64>(pcg32_fast::max()))
             return rng() % limit;
-        else
         return (static_cast<UInt64>(rng()) * (static_cast<UInt64>(pcg32_fast::max()) + 1ULL) + static_cast<UInt64>(rng())) % limit;
     }
 
@@ -277,7 +276,6 @@ private:
     {
         if (OnEmpty == ReservoirSamplerOnEmpty::THROW)
             throw DB::Exception(DB::ErrorCodes::LOGICAL_ERROR, "Quantile of empty ReservoirSampler");
-        else
         return NanLikeValueConstructor<ResultType, std::is_floating_point_v<ResultType>>::getValue();
     }
 };

src/AggregateFunctions/ReservoirSamplerDeterministic.h

@@ -271,7 +271,6 @@ private:
     {
         if (OnEmpty == ReservoirSamplerDeterministicOnEmpty::THROW)
             throw DB::Exception(DB::ErrorCodes::LOGICAL_ERROR, "Quantile of empty ReservoirSamplerDeterministic");
-        else
         return NanLikeValueConstructor<ResultType, std::is_floating_point_v<ResultType>>::getValue();
     }
 };

src/AggregateFunctions/SingleValueData.cpp

@@ -50,15 +50,13 @@ std::optional<size_t> SingleValueDataBase::getSmallestIndex(const IColumn & colu
                 index = i;
         return {index};
     }
-    else
-    {
+
     constexpr IColumn::PermutationSortDirection direction = IColumn::PermutationSortDirection::Ascending;
     constexpr IColumn::PermutationSortStability stability = IColumn::PermutationSortStability::Unstable;
     IColumn::Permutation permutation;
     constexpr UInt64 limit = 1;
     column.getPermutation(direction, stability, limit, nan_null_direction_hint, permutation);
     return {permutation[0]};
-    }
 }
 
 std::optional<size_t> SingleValueDataBase::getGreatestIndex(const IColumn & column, size_t row_begin, size_t row_end) const
@@ -77,15 +75,13 @@ std::optional<size_t> SingleValueDataBase::getGreatestIndex(const IColumn & colu
                 index = i;
         return {index};
     }
-    else
-    {
+
     constexpr IColumn::PermutationSortDirection direction = IColumn::PermutationSortDirection::Descending;
     constexpr IColumn::PermutationSortStability stability = IColumn::PermutationSortStability::Unstable;
     IColumn::Permutation permutation;
     constexpr UInt64 limit = 1;
     column.getPermutation(direction, stability, limit, nan_null_direction_hint, permutation);
     return {permutation[0]};
-    }
 }
 
 std::optional<size_t> SingleValueDataBase::getSmallestIndexNotNullIf(
@@ -247,7 +243,6 @@ bool SingleValueDataFixed<T>::setIfSmaller(const SingleValueDataFixed<T> & to, A
         set(to, arena);
         return true;
     }
-    else
     return false;
 }
 
@@ -259,7 +254,6 @@ bool SingleValueDataFixed<T>::setIfGreater(const SingleValueDataFixed<T> & to, A
         set(to, arena);
         return true;
     }
-    else
     return false;
 }
 
@@ -271,7 +265,6 @@ bool SingleValueDataFixed<T>::setIfSmaller(const IColumn & column, size_t row_nu
         set(column, row_num, arena);
         return true;
     }
-    else
     return false;
 }
 
@@ -283,7 +276,6 @@ bool SingleValueDataFixed<T>::setIfGreater(const IColumn & column, size_t row_nu
         set(column, row_num, arena);
         return true;
     }
-    else
     return false;
 }
 
@@ -544,7 +536,7 @@ std::optional<size_t> SingleValueDataFixed<T>::getGreatestIndexNotNullIf(
             }
             return opt;
         }
-        else if (!null_map)
+        if (!null_map)
         {
             opt = findExtremeMaxIf(vec.getData().data(), if_map, row_begin, row_end);
             if (!opt.has_value())
@@ -556,8 +548,7 @@ std::optional<size_t> SingleValueDataFixed<T>::getGreatestIndexNotNullIf(
             }
             return opt;
         }
-        else
-        {
+
         auto final_flags = mergeIfAndNullFlags(null_map, if_map, row_begin, row_end);
         opt = findExtremeMaxIf(vec.getData().data(), final_flags.get(), row_begin, row_end);
         if (!opt.has_value())
@@ -567,7 +558,7 @@ std::optional<size_t> SingleValueDataFixed<T>::getGreatestIndexNotNullIf(
             if (final_flags[i] && vec[i] == *opt)
                 return {i};
         }
-        }
+
         UNREACHABLE();
     }
     else
@@ -1218,7 +1209,6 @@ bool SingleValueDataString::setIfSmaller(const IColumn & column, size_t row_num,
         set(column, row_num, arena);
         return true;
     }
-    else
     return false;
 }
 
@@ -1230,7 +1220,6 @@ bool SingleValueDataString::setIfSmaller(const SingleValueDataBase & other, Aren
         changeImpl(to.getStringRef(), arena);
         return true;
     }
-    else
     return false;
 }
 
@@ -1243,7 +1232,6 @@ bool SingleValueDataString::setIfGreater(const IColumn & column, size_t row_num,
         set(column, row_num, arena);
         return true;
     }
-    else
     return false;
 }
 
@@ -1255,7 +1243,6 @@ bool SingleValueDataString::setIfGreater(const SingleValueDataBase & other, Aren
         changeImpl(to.getStringRef(), arena);
         return true;
     }
-    else
     return false;
 }
 
@@ -1317,8 +1304,7 @@ bool SingleValueDataGeneric::setIfSmaller(const IColumn & column, size_t row_num
         set(column, row_num, arena);
         return true;
     }
-    else
-    {
+
     Field new_value;
     column.get(row_num, new_value);
     if (new_value < value)
@@ -1326,9 +1312,7 @@ bool SingleValueDataGeneric::setIfSmaller(const IColumn & column, size_t row_num
         value = new_value;
         return true;
     }
-        else
     return false;
-    }
 }
 
 bool SingleValueDataGeneric::setIfSmaller(const SingleValueDataBase & other, Arena *)
@@ -1339,7 +1323,6 @@ bool SingleValueDataGeneric::setIfSmaller(const SingleValueDataBase & other, Are
         value = to.value;
         return true;
     }
-    else
     return false;
 }
 
@@ -1350,8 +1333,7 @@ bool SingleValueDataGeneric::setIfGreater(const IColumn & column, size_t row_num
         set(column, row_num, arena);
         return true;
     }
-    else
-    {
+
     Field new_value;
     column.get(row_num, new_value);
     if (new_value > value)
@@ -1359,9 +1341,7 @@ bool SingleValueDataGeneric::setIfGreater(const IColumn & column, size_t row_num
         value = new_value;
         return true;
     }
-        else
     return false;
-    }
 }
 
 bool SingleValueDataGeneric::setIfGreater(const SingleValueDataBase & other, Arena *)
@@ -1372,7 +1352,6 @@ bool SingleValueDataGeneric::setIfGreater(const SingleValueDataBase & other, Are
         value = to.value;
         return true;
     }
-    else
     return false;
 }
 

src/AggregateFunctions/ThetaSketchData.h

@@ -60,9 +60,8 @@ public:
     {
         if (sk_union)
             return static_cast<UInt64>(sk_union->get_result().get_estimate());
-        else if (sk_update)
+        if (sk_update)
             return static_cast<UInt64>(sk_update->get_estimate());
-        else
         return 0;
     }
 

src/AggregateFunctions/UniqVariadicHash.cpp

@@ -26,7 +26,6 @@ bool isAllArgumentsContiguousInMemory(const DataTypes & argument_types)
 
     if (single_argument_as_tuple)
         return check_all_arguments_are_contiguous_in_memory(single_argument_as_tuple->getElements());
-    else
     return check_all_arguments_are_contiguous_in_memory(argument_types);
 }
 

src/Analyzer/ColumnTransformers.cpp

@@ -163,8 +163,7 @@ void ExceptColumnTransformerNode::dumpTreeImpl(WriteBuffer & buffer, FormatState
         buffer << ", pattern: " << column_matcher->pattern();
         return;
     }
-    else
-    {
+
     buffer << ", identifiers: ";
 
     size_t except_column_names_size = except_column_names.size();
@@ -175,7 +174,6 @@ void ExceptColumnTransformerNode::dumpTreeImpl(WriteBuffer & buffer, FormatState
         if (i + 1 != except_column_names_size)
             buffer << ", ";
     }
-    }
 }
 
 bool ExceptColumnTransformerNode::isEqualImpl(const IQueryTreeNode & rhs, CompareOptions) const
@@ -190,9 +188,9 @@ bool ExceptColumnTransformerNode::isEqualImpl(const IQueryTreeNode & rhs, Compar
 
     if (!column_matcher && !rhs_column_matcher)
         return true;
-    else if (column_matcher && !rhs_column_matcher)
+    if (column_matcher && !rhs_column_matcher)
         return false;
-    else if (!column_matcher && rhs_column_matcher)
+    if (!column_matcher && rhs_column_matcher)
         return false;
 
     return column_matcher->pattern() == rhs_column_matcher->pattern();

src/Analyzer/FunctionNode.cpp

@@ -173,9 +173,9 @@ bool FunctionNode::isEqualImpl(const IQueryTreeNode & rhs, CompareOptions compar
 
     if (lhs_result_type && rhs_result_type && !lhs_result_type->equals(*rhs_result_type))
         return false;
-    else if (lhs_result_type && !rhs_result_type)
+    if (lhs_result_type && !rhs_result_type)
         return false;
-    else if (!lhs_result_type && rhs_result_type)
+    if (!lhs_result_type && rhs_result_type)
         return false;
 
     return true;

src/Analyzer/IQueryTreeNode.cpp

@@ -127,9 +127,9 @@ bool IQueryTreeNode::isEqual(const IQueryTreeNode & rhs, CompareOptions compare_
 
             if (!lhs_child && !rhs_child)
                 continue;
-            else if (lhs_child && !rhs_child)
+            if (lhs_child && !rhs_child)
                 return false;
-            else if (!lhs_child && rhs_child)
+            if (!lhs_child && rhs_child)
                 return false;
 
             nodes_to_process.emplace_back(lhs_child.get(), rhs_child.get());
@@ -150,9 +150,9 @@ bool IQueryTreeNode::isEqual(const IQueryTreeNode & rhs, CompareOptions compare_
 
             if (!lhs_strong_pointer && !rhs_strong_pointer)
                 continue;
-            else if (lhs_strong_pointer && !rhs_strong_pointer)
+            if (lhs_strong_pointer && !rhs_strong_pointer)
                 return false;
-            else if (!lhs_strong_pointer && rhs_strong_pointer)
+            if (!lhs_strong_pointer && rhs_strong_pointer)
                 return false;
 
             nodes_to_process.emplace_back(lhs_strong_pointer.get(), rhs_strong_pointer.get());

src/Analyzer/InDepthQueryTreeVisitor.h

@@ -202,7 +202,6 @@ private:
             }
             return;
         }
-        else
         visit(child);
     }
 

src/Analyzer/MatcherNode.cpp

@@ -173,9 +173,9 @@ bool MatcherNode::isEqualImpl(const IQueryTreeNode & rhs, CompareOptions) const
 
     if (!columns_matcher && !rhs_columns_matcher)
         return true;
-    else if (columns_matcher && !rhs_columns_matcher)
+    if (columns_matcher && !rhs_columns_matcher)
         return false;
-    else if (!columns_matcher && rhs_columns_matcher)
+    if (!columns_matcher && rhs_columns_matcher)
         return false;
 
     return columns_matcher->pattern() == rhs_columns_matcher->pattern();

src/Analyzer/Passes/AggregateFunctionsArithmericOperationsPass.cpp

@@ -118,9 +118,8 @@ public:
         {
             if (aggregate_function_name == "min")
                 return "max";
-            else if (aggregate_function_name == "max")
+            if (aggregate_function_name == "max")
                 return "min";
-            else
             return aggregate_function_name;
         };
 

src/Analyzer/Passes/CNF.cpp

@@ -486,7 +486,6 @@ CNF & CNF::reduce()
             statements = filterCNFSubsets(statements);
             return *this;
         }
-        else
         statements = new_statements;
     }
 }

src/Analyzer/Passes/ConvertQueryToCNFPass.cpp

@@ -184,7 +184,7 @@ StorageSnapshotPtr getStorageSnapshot(const QueryTreeNodePtr & node)
     StorageSnapshotPtr storage_snapshot{nullptr};
     if (auto * table_node = node->as<TableNode>())
         return table_node->getStorageSnapshot();
-    else if (auto * table_function_node = node->as<TableFunctionNode>())
+    if (auto * table_function_node = node->as<TableFunctionNode>())
         return table_function_node->getStorageSnapshot();
 
     return nullptr;

src/Analyzer/Passes/IfTransformStringsToEnumPass.cpp

@@ -43,7 +43,6 @@ DataTypePtr getEnumType(const std::set<std::string> & string_values)
 {
     if (string_values.size() >= 255)
         return getDataEnumType<DataTypeEnum16>(string_values);
-    else
     return getDataEnumType<DataTypeEnum8>(string_values);
 }
 

src/Analyzer/Passes/OptimizeDateOrDateTimeConverterWithPreimagePass.cpp

@@ -165,27 +165,26 @@ private:
                 createFunctionNode("greaterOrEquals", column_node, std::make_shared<ConstantNode>(start_date_or_date_time)),
                 createFunctionNode("less", column_node, std::make_shared<ConstantNode>(end_date_or_date_time)));
         }
-        else if (comparator == "notEquals")
+        if (comparator == "notEquals")
         {
             return createFunctionNode(
                 "or",
                 createFunctionNode("less", column_node, std::make_shared<ConstantNode>(start_date_or_date_time)),
                 createFunctionNode("greaterOrEquals", column_node, std::make_shared<ConstantNode>(end_date_or_date_time)));
         }
-        else if (comparator == "greater")
+        if (comparator == "greater")
         {
             return createFunctionNode("greaterOrEquals", column_node, std::make_shared<ConstantNode>(end_date_or_date_time));
         }
-        else if (comparator == "lessOrEquals")
+        if (comparator == "lessOrEquals")
         {
             return createFunctionNode("less", column_node, std::make_shared<ConstantNode>(end_date_or_date_time));
         }
-        else if (comparator == "less" || comparator == "greaterOrEquals")
+        if (comparator == "less" || comparator == "greaterOrEquals")
         {
             return createFunctionNode(comparator, column_node, std::make_shared<ConstantNode>(start_date_or_date_time));
         }
-        else [[unlikely]]
-        {
+        [[unlikely]] {
             throw Exception(
                 ErrorCodes::LOGICAL_ERROR,
                 "Expected equals, notEquals, less, lessOrEquals, greater, greaterOrEquals. Actual {}",

src/Analyzer/Resolve/IdentifierResolver.cpp

@@ -552,9 +552,9 @@ QueryTreeNodePtr IdentifierResolver::tryResolveIdentifierFromExpressionArguments
     auto node_type = it->second->getNodeType();
     if (identifier_lookup.isExpressionLookup() && !isExpressionNodeType(node_type))
         return {};
-    else if (identifier_lookup.isTableExpressionLookup() && !isTableExpressionNodeType(node_type))
+    if (identifier_lookup.isTableExpressionLookup() && !isTableExpressionNodeType(node_type))
         return {};
-    else if (identifier_lookup.isFunctionLookup() && !isFunctionExpressionNodeType(node_type))
+    if (identifier_lookup.isFunctionLookup() && !isFunctionExpressionNodeType(node_type))
         return {};
 
     if (!resolve_full_identifier && identifier_lookup.identifier.isCompound() && identifier_lookup.isExpressionLookup())
@@ -638,9 +638,8 @@ bool IdentifierResolver::tryBindIdentifierToTableExpression(const IdentifierLook
 
         if (parts_size == 1 && path_start == table_name)
             return true;
-        else if (parts_size == 2 && path_start == database_name && identifier[1] == table_name)
+        if (parts_size == 2 && path_start == database_name && identifier[1] == table_name)
             return true;
-        else
         return false;
     }
 
@@ -910,9 +909,8 @@ QueryTreeNodePtr IdentifierResolver::tryResolveIdentifierFromTableExpression(con
 
         if (parts_size == 1 && path_start == table_name)
             return table_expression_node;
-        else if (parts_size == 2 && path_start == database_name && identifier[1] == table_name)
+        if (parts_size == 2 && path_start == database_name && identifier[1] == table_name)
             return table_expression_node;
-        else
         return {};
     }
 

src/Analyzer/Resolve/QueryAnalyzer.cpp

@@ -1219,9 +1219,10 @@ QueryTreeNodePtr QueryAnalyzer::tryResolveIdentifierFromAliases(const Identifier
                 scope,
                 identifier_resolve_settings.allow_to_check_join_tree /* can_be_not_found */);
         }
-        else if (identifier_lookup.isFunctionLookup() || identifier_lookup.isTableExpressionLookup())
+        if (identifier_lookup.isFunctionLookup() || identifier_lookup.isTableExpressionLookup())
         {
-            throw Exception(ErrorCodes::BAD_ARGUMENTS,
+            throw Exception(
+                ErrorCodes::BAD_ARGUMENTS,
                 "Compound identifier '{}' cannot be resolved as {}. In scope {}",
                 identifier_lookup.identifier.getFullName(),
                 identifier_lookup.isFunctionLookup() ? "function" : "table expression",
@@ -1307,7 +1308,7 @@ IdentifierResolveResult QueryAnalyzer::tryResolveIdentifierInParentScopes(const
             {
                 return lookup_result;
             }
-            else if (auto * resolved_function = resolved_identifier->as<FunctionNode>())
+            if (auto * resolved_function = resolved_identifier->as<FunctionNode>())
             {
                 /// Special case: scalar subquery was executed and replaced by __getScalar function.
                 /// Handle it as a constant.
@@ -3173,14 +3174,14 @@ ProjectionNames QueryAnalyzer::resolveFunction(QueryTreeNodePtr & node, Identifi
             node = std::move(result_list);
             return result_projection_names;
         }
-        else if (function_name == "grouping")
+        if (function_name == "grouping")
         {
             /// It is responsibility of planner to perform additional handling of grouping function
             if (function_arguments_size == 0)
-                throw Exception(ErrorCodes::TOO_FEW_ARGUMENTS_FOR_FUNCTION,
-                    "Function GROUPING expects at least one argument");
-            else if (function_arguments_size > 64)
-                throw Exception(ErrorCodes::TOO_MANY_ARGUMENTS_FOR_FUNCTION,
+                throw Exception(ErrorCodes::TOO_FEW_ARGUMENTS_FOR_FUNCTION, "Function GROUPING expects at least one argument");
+            if (function_arguments_size > 64)
+                throw Exception(
+                    ErrorCodes::TOO_MANY_ARGUMENTS_FOR_FUNCTION,
                     "Function GROUPING can have up to 64 arguments, but {} provided",
                     function_arguments_size);
             checkFunctionNodeHasEmptyNullsAction(function_node);
@@ -3744,8 +3745,8 @@ ProjectionNames QueryAnalyzer::resolveExpressionNode(
                 resolved_expression_it = resolved_expressions.find(node);
                 if (resolved_expression_it != resolved_expressions.end())
                     return resolved_expression_it->second;
-                else
-                    throw Exception(ErrorCodes::LOGICAL_ERROR,
+                throw Exception(
+                    ErrorCodes::LOGICAL_ERROR,
                     "Identifier '{}' resolve into list node and list node projection names are not initialized. In scope {}",
                     unresolved_identifier.getFullName(),
                     scope.scope_node->formatASTForErrorMessage());
@@ -4212,7 +4213,7 @@ NamesAndTypes QueryAnalyzer::resolveProjectionExpressionNodeList(QueryTreeNodePt
 
     for (size_t i = 0; i < projection_nodes_size; ++i)
     {
-        auto projection_node = projection_nodes[i];
+        const auto & projection_node = projection_nodes[i];
 
         if (!IdentifierResolver::isExpressionNodeType(projection_node->getNodeType()))
             throw Exception(ErrorCodes::UNSUPPORTED_METHOD,
@@ -4628,10 +4629,7 @@ void QueryAnalyzer::resolveTableFunction(QueryTreeNodePtr & table_function_node,
                 "Unknown table function {}. Maybe you meant: {}",
                 table_function_name,
                 DB::toString(hints));
-        else
-            throw Exception(ErrorCodes::UNKNOWN_FUNCTION,
-                "Unknown table function {}",
-                table_function_name);
+        throw Exception(ErrorCodes::UNKNOWN_FUNCTION, "Unknown table function {}", table_function_name);
     }
 
     QueryTreeNodes result_table_function_arguments;
@@ -4667,7 +4665,7 @@ void QueryAnalyzer::resolveTableFunction(QueryTreeNodePtr & table_function_node,
 
             continue;
         }
-        else if (auto * table_function_argument_function = table_function_argument->as<FunctionNode>())
+        if (auto * table_function_argument_function = table_function_argument->as<FunctionNode>())
         {
             const auto & table_function_argument_function_name = table_function_argument_function->getFunctionName();
             if (TableFunctionFactory::instance().isTableFunctionName(table_function_argument_function_name))

src/Analyzer/Resolve/QueryExpressionsAliasVisitor.h

@@ -50,7 +50,7 @@ public:
             updateAliasesIfNeeded(child, true /*is_lambda_node*/);
             return false;
         }
-        else if (auto * query_tree_node = child->as<QueryNode>())
+        if (auto * query_tree_node = child->as<QueryNode>())
         {
             if (query_tree_node->isCTE())
                 return false;
@@ -58,7 +58,7 @@ public:
             updateAliasesIfNeeded(child, false /*is_lambda_node*/);
             return false;
         }
-        else if (auto * union_node = child->as<UnionNode>())
+        if (auto * union_node = child->as<UnionNode>())
         {
             if (union_node->isCTE())
                 return false;

src/Analyzer/SortNode.cpp

@@ -81,9 +81,9 @@ bool SortNode::isEqualImpl(const IQueryTreeNode & rhs, CompareOptions) const
 
     if (!collator && !rhs_typed.collator)
         return true;
-    else if (collator && !rhs_typed.collator)
+    if (collator && !rhs_typed.collator)
         return false;
-    else if (!collator && rhs_typed.collator)
+    if (!collator && rhs_typed.collator)
         return false;
 
     return collator->getLocale() == rhs_typed.collator->getLocale();

src/Analyzer/UnionNode.cpp

@@ -170,7 +170,7 @@ bool UnionNode::isEqualImpl(const IQueryTreeNode & rhs, CompareOptions) const
     if (recursive_cte_table && rhs_typed.recursive_cte_table &&
         recursive_cte_table->getStorageID() != rhs_typed.recursive_cte_table->getStorageID())
         return false;
-    else if ((recursive_cte_table && !rhs_typed.recursive_cte_table) || (!recursive_cte_table && rhs_typed.recursive_cte_table))
+    if ((recursive_cte_table && !rhs_typed.recursive_cte_table) || (!recursive_cte_table && rhs_typed.recursive_cte_table))
         return false;
 
     return is_subquery == rhs_typed.is_subquery && is_cte == rhs_typed.is_cte && is_recursive_cte == rhs_typed.is_recursive_cte

src/Analyzer/Utils.cpp

@@ -156,19 +156,19 @@ std::string getGlobalInFunctionNameForLocalInFunctionName(const std::string & fu
 {
     if (function_name == "in")
         return "globalIn";
-    else if (function_name == "notIn")
+    if (function_name == "notIn")
         return "globalNotIn";
-    else if (function_name == "nullIn")
+    if (function_name == "nullIn")
         return "globalNullIn";
-    else if (function_name == "notNullIn")
+    if (function_name == "notNullIn")
         return "globalNotNullIn";
-    else if (function_name == "inIgnoreSet")
+    if (function_name == "inIgnoreSet")
         return "globalInIgnoreSet";
-    else if (function_name == "notInIgnoreSet")
+    if (function_name == "notInIgnoreSet")
         return "globalNotInIgnoreSet";
-    else if (function_name == "nullInIgnoreSet")
+    if (function_name == "nullInIgnoreSet")
         return "globalNullInIgnoreSet";
-    else if (function_name == "notNullInIgnoreSet")
+    if (function_name == "notNullInIgnoreSet")
         return "globalNotNullInIgnoreSet";
 
     throw Exception(ErrorCodes::BAD_ARGUMENTS, "Invalid local IN function name {}", function_name);

src/Analyzer/ValidationUtils.cpp

@@ -173,9 +173,9 @@ private:
 
                 if (!lhs_child && !rhs_child)
                     continue;
-                else if (lhs_child && !rhs_child)
+                if (lhs_child && !rhs_child)
                     return false;
-                else if (!lhs_child && rhs_child)
+                if (!lhs_child && rhs_child)
                     return false;
 
                 nodes_to_process.emplace_back(lhs_child.get(), rhs_child.get());

src/Backups/BackupEntriesCollector.cpp

@@ -182,17 +182,15 @@ Strings BackupEntriesCollector::setStage(const String & new_stage, const String
     {
         return backup_coordination->waitForStage(new_stage, on_cluster_first_sync_timeout);
     }
-    else if (new_stage.starts_with(Stage::GATHERING_METADATA))
+    if (new_stage.starts_with(Stage::GATHERING_METADATA))
     {
         auto current_time = std::chrono::steady_clock::now();
         auto end_of_timeout = std::max(current_time, collect_metadata_end_time);
         return backup_coordination->waitForStage(
             new_stage, std::chrono::duration_cast<std::chrono::milliseconds>(end_of_timeout - current_time));
     }
-    else
-    {
+
     return backup_coordination->waitForStage(new_stage);
-    }
 }
 
 void BackupEntriesCollector::checkIsQueryCancelled() const
@@ -716,23 +714,20 @@ bool BackupEntriesCollector::compareWithPrevious(String & mismatch_description)
         {
             if (mismatch->first == p_mismatch->first)
                 return {MismatchType::CHANGED, mismatch->first};
-            else if (mismatch->first < p_mismatch->first)
+            if (mismatch->first < p_mismatch->first)
                 return {MismatchType::ADDED, mismatch->first};
-            else
             return {MismatchType::REMOVED, mismatch->first};
         }
-        else if (mismatch != metadata.end())
+        if (mismatch != metadata.end())
         {
             return {MismatchType::ADDED, mismatch->first};
         }
-        else if (p_mismatch != previous_metadata.end())
+        if (p_mismatch != previous_metadata.end())
         {
             return {MismatchType::REMOVED, p_mismatch->first};
         }
-        else
-        {
+
         return {MismatchType::NONE, {}};
-        }
     };
 
     /// Databases must be the same as during the previous scan.

src/Backups/BackupEntryFromAppendOnlyFile.cpp

@@ -14,9 +14,8 @@ namespace
     {
         if (!unencrypted_file_size)
             return copy_encrypted ? disk->getEncryptedFileSize(file_path) : disk->getFileSize(file_path);
-        else if (copy_encrypted)
+        if (copy_encrypted)
             return disk->getEncryptedFileSize(*unencrypted_file_size);
-        else
         return *unencrypted_file_size;
     }
 }

src/Backups/BackupEntryFromImmutableFile.cpp

@@ -39,7 +39,6 @@ std::unique_ptr<SeekableReadBuffer> BackupEntryFromImmutableFile::getReadBuffer(
 {
     if (copy_encrypted)
         return disk->readEncryptedFile(file_path, read_settings);
-    else
     return disk->readFile(file_path, read_settings);
 }