feat: add WriteHint and PrimaryKeyEncoding to Mutation (#209)

* feat: add `write_hint` to `Mutation`

* feat: introduce `PrimaryKeyEncoding` and `WriteHint`

c++/greptime/v1/wal.pb.cc

@@ -22,9 +22,23 @@ namespace _pbi = _pb::internal;
 
 namespace greptime {
 namespace v1 {
+PROTOBUF_CONSTEXPR WriteHint::WriteHint(
+    ::_pbi::ConstantInitialized): _impl_{
+    /*decltype(_impl_.primary_key_encoding_)*/0
+  , /*decltype(_impl_._cached_size_)*/{}} {}
+struct WriteHintDefaultTypeInternal {
+  PROTOBUF_CONSTEXPR WriteHintDefaultTypeInternal()
+      : _instance(::_pbi::ConstantInitialized{}) {}
+  ~WriteHintDefaultTypeInternal() {}
+  union {
+    WriteHint _instance;
+  };
+};
+PROTOBUF_ATTRIBUTE_NO_DESTROY PROTOBUF_CONSTINIT PROTOBUF_ATTRIBUTE_INIT_PRIORITY1 WriteHintDefaultTypeInternal _WriteHint_default_instance_;
 PROTOBUF_CONSTEXPR Mutation::Mutation(
     ::_pbi::ConstantInitialized): _impl_{
     /*decltype(_impl_.rows_)*/nullptr
+  , /*decltype(_impl_.write_hint_)*/nullptr
   , /*decltype(_impl_.sequence_)*/uint64_t{0u}
   , /*decltype(_impl_.op_type_)*/0
   , /*decltype(_impl_._cached_size_)*/{}} {}
@@ -52,11 +66,18 @@ struct WalEntryDefaultTypeInternal {
 PROTOBUF_ATTRIBUTE_NO_DESTROY PROTOBUF_CONSTINIT PROTOBUF_ATTRIBUTE_INIT_PRIORITY1 WalEntryDefaultTypeInternal _WalEntry_default_instance_;
 }  // namespace v1
 }  // namespace greptime
-static ::_pb::Metadata file_level_metadata_greptime_2fv1_2fwal_2eproto[2];
+static ::_pb::Metadata file_level_metadata_greptime_2fv1_2fwal_2eproto[3];
-static const ::_pb::EnumDescriptor* file_level_enum_descriptors_greptime_2fv1_2fwal_2eproto[1];
+static const ::_pb::EnumDescriptor* file_level_enum_descriptors_greptime_2fv1_2fwal_2eproto[2];
 static constexpr ::_pb::ServiceDescriptor const** file_level_service_descriptors_greptime_2fv1_2fwal_2eproto = nullptr;
 
 const uint32_t TableStruct_greptime_2fv1_2fwal_2eproto::offsets[] PROTOBUF_SECTION_VARIABLE(protodesc_cold) = {
+  ~0u,  // no _has_bits_
+  PROTOBUF_FIELD_OFFSET(::greptime::v1::WriteHint, _internal_metadata_),
+  ~0u,  // no _extensions_
+  ~0u,  // no _oneof_case_
+  ~0u,  // no _weak_field_map_
+  ~0u,  // no _inlined_string_donated_
+  PROTOBUF_FIELD_OFFSET(::greptime::v1::WriteHint, _impl_.primary_key_encoding_),
   ~0u,  // no _has_bits_
   PROTOBUF_FIELD_OFFSET(::greptime::v1::Mutation, _internal_metadata_),
   ~0u,  // no _extensions_
@@ -66,6 +87,7 @@ const uint32_t TableStruct_greptime_2fv1_2fwal_2eproto::offsets[] PROTOBUF_SECTI
   PROTOBUF_FIELD_OFFSET(::greptime::v1::Mutation, _impl_.op_type_),
   PROTOBUF_FIELD_OFFSET(::greptime::v1::Mutation, _impl_.sequence_),
   PROTOBUF_FIELD_OFFSET(::greptime::v1::Mutation, _impl_.rows_),
+  PROTOBUF_FIELD_OFFSET(::greptime::v1::Mutation, _impl_.write_hint_),
   ~0u,  // no _has_bits_
   PROTOBUF_FIELD_OFFSET(::greptime::v1::WalEntry, _internal_metadata_),
   ~0u,  // no _extensions_
@@ -75,33 +97,39 @@ const uint32_t TableStruct_greptime_2fv1_2fwal_2eproto::offsets[] PROTOBUF_SECTI
   PROTOBUF_FIELD_OFFSET(::greptime::v1::WalEntry, _impl_.mutations_),
 };
 static const ::_pbi::MigrationSchema schemas[] PROTOBUF_SECTION_VARIABLE(protodesc_cold) = {
-  { 0, -1, -1, sizeof(::greptime::v1::Mutation)},
+  { 0, -1, -1, sizeof(::greptime::v1::WriteHint)},
-  { 9, -1, -1, sizeof(::greptime::v1::WalEntry)},
+  { 7, -1, -1, sizeof(::greptime::v1::Mutation)},
+  { 17, -1, -1, sizeof(::greptime::v1::WalEntry)},
 };
 
 static const ::_pb::Message* const file_default_instances[] = {
+  &::greptime::v1::_WriteHint_default_instance_._instance,
   &::greptime::v1::_Mutation_default_instance_._instance,
   &::greptime::v1::_WalEntry_default_instance_._instance,
 };
 
 const char descriptor_table_protodef_greptime_2fv1_2fwal_2eproto[] PROTOBUF_SECTION_VARIABLE(protodesc_cold) =
   "\n\025greptime/v1/wal.proto\022\013greptime.v1\032\025gr"
-  "eptime/v1/row.proto\"c\n\010Mutation\022$\n\007op_ty"
+  "eptime/v1/row.proto\"J\n\tWriteHint\022=\n\024prim"
-  "pe\030\001 \001(\0162\023.greptime.v1.OpType\022\020\n\010sequenc"
+  "ary_key_encoding\030\001 \001(\0162\037.greptime.v1.Pri"
-  "e\030\002 \001(\004\022\037\n\004rows\030\003 \001(\0132\021.greptime.v1.Rows"
+  "maryKeyEncoding\"\217\001\n\010Mutation\022$\n\007op_type\030"
-  "\"4\n\010WalEntry\022(\n\tmutations\030\001 \003(\0132\025.grepti"
+  "\001 \001(\0162\023.greptime.v1.OpType\022\020\n\010sequence\030\002"
-  "me.v1.Mutation*\035\n\006OpType\022\n\n\006DELETE\020\000\022\007\n\003"
+  " \001(\004\022\037\n\004rows\030\003 \001(\0132\021.greptime.v1.Rows\022*\n"
-  "PUT\020\001B7Z5github.com/GreptimeTeam/greptim"
+  "\nwrite_hint\030\004 \001(\0132\026.greptime.v1.WriteHin"
-  "e-proto/go/greptime/v1b\006proto3"
+  "t\"4\n\010WalEntry\022(\n\tmutations\030\001 \003(\0132\025.grept"
+  "ime.v1.Mutation*\035\n\006OpType\022\n\n\006DELETE\020\000\022\007\n"
+  "\003PUT\020\001*+\n\022PrimaryKeyEncoding\022\t\n\005DENSE\020\000\022"
+  "\n\n\006SPARSE\020\001B7Z5github.com/GreptimeTeam/g"
+  "reptime-proto/go/greptime/v1b\006proto3"
   ;
 static const ::_pbi::DescriptorTable* const descriptor_table_greptime_2fv1_2fwal_2eproto_deps[1] = {
   &::descriptor_table_greptime_2fv1_2frow_2eproto,
 };
 static ::_pbi::once_flag descriptor_table_greptime_2fv1_2fwal_2eproto_once;
 const ::_pbi::DescriptorTable descriptor_table_greptime_2fv1_2fwal_2eproto = {
-    false, false, 310, descriptor_table_protodef_greptime_2fv1_2fwal_2eproto,
+    false, false, 476, descriptor_table_protodef_greptime_2fv1_2fwal_2eproto,
     "greptime/v1/wal.proto",
-    &descriptor_table_greptime_2fv1_2fwal_2eproto_once, descriptor_table_greptime_2fv1_2fwal_2eproto_deps, 1, 2,
+    &descriptor_table_greptime_2fv1_2fwal_2eproto_once, descriptor_table_greptime_2fv1_2fwal_2eproto_deps, 1, 3,
     schemas, file_default_instances, TableStruct_greptime_2fv1_2fwal_2eproto::offsets,
     file_level_metadata_greptime_2fv1_2fwal_2eproto, file_level_enum_descriptors_greptime_2fv1_2fwal_2eproto,
     file_level_service_descriptors_greptime_2fv1_2fwal_2eproto,
@@ -128,18 +156,218 @@ bool OpType_IsValid(int value) {
   }
 }
 
+const ::PROTOBUF_NAMESPACE_ID::EnumDescriptor* PrimaryKeyEncoding_descriptor() {
+  ::PROTOBUF_NAMESPACE_ID::internal::AssignDescriptors(&descriptor_table_greptime_2fv1_2fwal_2eproto);
+  return file_level_enum_descriptors_greptime_2fv1_2fwal_2eproto[1];
+}
+bool PrimaryKeyEncoding_IsValid(int value) {
+  switch (value) {
+    case 0:
+    case 1:
+      return true;
+    default:
+      return false;
+  }
+}
+
+
+// ===================================================================
+
+class WriteHint::_Internal {
+ public:
+};
+
+WriteHint::WriteHint(::PROTOBUF_NAMESPACE_ID::Arena* arena,
+                         bool is_message_owned)
+  : ::PROTOBUF_NAMESPACE_ID::Message(arena, is_message_owned) {
+  SharedCtor(arena, is_message_owned);
+  // @@protoc_insertion_point(arena_constructor:greptime.v1.WriteHint)
+}
+WriteHint::WriteHint(const WriteHint& from)
+  : ::PROTOBUF_NAMESPACE_ID::Message() {
+  WriteHint* const _this = this; (void)_this;
+  new (&_impl_) Impl_{
+      decltype(_impl_.primary_key_encoding_){}
+    , /*decltype(_impl_._cached_size_)*/{}};
+
+  _internal_metadata_.MergeFrom<::PROTOBUF_NAMESPACE_ID::UnknownFieldSet>(from._internal_metadata_);
+  _this->_impl_.primary_key_encoding_ = from._impl_.primary_key_encoding_;
+  // @@protoc_insertion_point(copy_constructor:greptime.v1.WriteHint)
+}
+
+inline void WriteHint::SharedCtor(
+    ::_pb::Arena* arena, bool is_message_owned) {
+  (void)arena;
+  (void)is_message_owned;
+  new (&_impl_) Impl_{
+      decltype(_impl_.primary_key_encoding_){0}
+    , /*decltype(_impl_._cached_size_)*/{}
+  };
+}
+
+WriteHint::~WriteHint() {
+  // @@protoc_insertion_point(destructor:greptime.v1.WriteHint)
+  if (auto *arena = _internal_metadata_.DeleteReturnArena<::PROTOBUF_NAMESPACE_ID::UnknownFieldSet>()) {
+  (void)arena;
+    return;
+  }
+  SharedDtor();
+}
+
+inline void WriteHint::SharedDtor() {
+  GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
+}
+
+void WriteHint::SetCachedSize(int size) const {
+  _impl_._cached_size_.Set(size);
+}
+
+void WriteHint::Clear() {
+// @@protoc_insertion_point(message_clear_start:greptime.v1.WriteHint)
+  uint32_t cached_has_bits = 0;
+  // Prevent compiler warnings about cached_has_bits being unused
+  (void) cached_has_bits;
+
+  _impl_.primary_key_encoding_ = 0;
+  _internal_metadata_.Clear<::PROTOBUF_NAMESPACE_ID::UnknownFieldSet>();
+}
+
+const char* WriteHint::_InternalParse(const char* ptr, ::_pbi::ParseContext* ctx) {
+#define CHK_(x) if (PROTOBUF_PREDICT_FALSE(!(x))) goto failure
+  while (!ctx->Done(&ptr)) {
+    uint32_t tag;
+    ptr = ::_pbi::ReadTag(ptr, &tag);
+    switch (tag >> 3) {
+      // .greptime.v1.PrimaryKeyEncoding primary_key_encoding = 1;
+      case 1:
+        if (PROTOBUF_PREDICT_TRUE(static_cast<uint8_t>(tag) == 8)) {
+          uint64_t val = ::PROTOBUF_NAMESPACE_ID::internal::ReadVarint64(&ptr);
+          CHK_(ptr);
+          _internal_set_primary_key_encoding(static_cast<::greptime::v1::PrimaryKeyEncoding>(val));
+        } else
+          goto handle_unusual;
+        continue;
+      default:
+        goto handle_unusual;
+    }  // switch
+  handle_unusual:
+    if ((tag == 0) || ((tag & 7) == 4)) {
+      CHK_(ptr);
+      ctx->SetLastTag(tag);
+      goto message_done;
+    }
+    ptr = UnknownFieldParse(
+        tag,
+        _internal_metadata_.mutable_unknown_fields<::PROTOBUF_NAMESPACE_ID::UnknownFieldSet>(),
+        ptr, ctx);
+    CHK_(ptr != nullptr);
+  }  // while
+message_done:
+  return ptr;
+failure:
+  ptr = nullptr;
+  goto message_done;
+#undef CHK_
+}
+
+uint8_t* WriteHint::_InternalSerialize(
+    uint8_t* target, ::PROTOBUF_NAMESPACE_ID::io::EpsCopyOutputStream* stream) const {
+  // @@protoc_insertion_point(serialize_to_array_start:greptime.v1.WriteHint)
+  uint32_t cached_has_bits = 0;
+  (void) cached_has_bits;
+
+  // .greptime.v1.PrimaryKeyEncoding primary_key_encoding = 1;
+  if (this->_internal_primary_key_encoding() != 0) {
+    target = stream->EnsureSpace(target);
+    target = ::_pbi::WireFormatLite::WriteEnumToArray(
+      1, this->_internal_primary_key_encoding(), target);
+  }
+
+  if (PROTOBUF_PREDICT_FALSE(_internal_metadata_.have_unknown_fields())) {
+    target = ::_pbi::WireFormat::InternalSerializeUnknownFieldsToArray(
+        _internal_metadata_.unknown_fields<::PROTOBUF_NAMESPACE_ID::UnknownFieldSet>(::PROTOBUF_NAMESPACE_ID::UnknownFieldSet::default_instance), target, stream);
+  }
+  // @@protoc_insertion_point(serialize_to_array_end:greptime.v1.WriteHint)
+  return target;
+}
+
+size_t WriteHint::ByteSizeLong() const {
+// @@protoc_insertion_point(message_byte_size_start:greptime.v1.WriteHint)
+  size_t total_size = 0;
+
+  uint32_t cached_has_bits = 0;
+  // Prevent compiler warnings about cached_has_bits being unused
+  (void) cached_has_bits;
+
+  // .greptime.v1.PrimaryKeyEncoding primary_key_encoding = 1;
+  if (this->_internal_primary_key_encoding() != 0) {
+    total_size += 1 +
+      ::_pbi::WireFormatLite::EnumSize(this->_internal_primary_key_encoding());
+  }
+
+  return MaybeComputeUnknownFieldsSize(total_size, &_impl_._cached_size_);
+}
+
+const ::PROTOBUF_NAMESPACE_ID::Message::ClassData WriteHint::_class_data_ = {
+    ::PROTOBUF_NAMESPACE_ID::Message::CopyWithSourceCheck,
+    WriteHint::MergeImpl
+};
+const ::PROTOBUF_NAMESPACE_ID::Message::ClassData*WriteHint::GetClassData() const { return &_class_data_; }
+
+
+void WriteHint::MergeImpl(::PROTOBUF_NAMESPACE_ID::Message& to_msg, const ::PROTOBUF_NAMESPACE_ID::Message& from_msg) {
+  auto* const _this = static_cast<WriteHint*>(&to_msg);
+  auto& from = static_cast<const WriteHint&>(from_msg);
+  // @@protoc_insertion_point(class_specific_merge_from_start:greptime.v1.WriteHint)
+  GOOGLE_DCHECK_NE(&from, _this);
+  uint32_t cached_has_bits = 0;
+  (void) cached_has_bits;
+
+  if (from._internal_primary_key_encoding() != 0) {
+    _this->_internal_set_primary_key_encoding(from._internal_primary_key_encoding());
+  }
+  _this->_internal_metadata_.MergeFrom<::PROTOBUF_NAMESPACE_ID::UnknownFieldSet>(from._internal_metadata_);
+}
+
+void WriteHint::CopyFrom(const WriteHint& from) {
+// @@protoc_insertion_point(class_specific_copy_from_start:greptime.v1.WriteHint)
+  if (&from == this) return;
+  Clear();
+  MergeFrom(from);
+}
+
+bool WriteHint::IsInitialized() const {
+  return true;
+}
+
+void WriteHint::InternalSwap(WriteHint* other) {
+  using std::swap;
+  _internal_metadata_.InternalSwap(&other->_internal_metadata_);
+  swap(_impl_.primary_key_encoding_, other->_impl_.primary_key_encoding_);
+}
+
+::PROTOBUF_NAMESPACE_ID::Metadata WriteHint::GetMetadata() const {
+  return ::_pbi::AssignDescriptors(
+      &descriptor_table_greptime_2fv1_2fwal_2eproto_getter, &descriptor_table_greptime_2fv1_2fwal_2eproto_once,
+      file_level_metadata_greptime_2fv1_2fwal_2eproto[0]);
+}
 
 // ===================================================================
 
 class Mutation::_Internal {
  public:
   static const ::greptime::v1::Rows& rows(const Mutation* msg);
+  static const ::greptime::v1::WriteHint& write_hint(const Mutation* msg);
 };
 
 const ::greptime::v1::Rows&
 Mutation::_Internal::rows(const Mutation* msg) {
   return *msg->_impl_.rows_;
 }
+const ::greptime::v1::WriteHint&
+Mutation::_Internal::write_hint(const Mutation* msg) {
+  return *msg->_impl_.write_hint_;
+}
 void Mutation::clear_rows() {
   if (GetArenaForAllocation() == nullptr && _impl_.rows_ != nullptr) {
     delete _impl_.rows_;
@@ -157,6 +385,7 @@ Mutation::Mutation(const Mutation& from)
   Mutation* const _this = this; (void)_this;
   new (&_impl_) Impl_{
       decltype(_impl_.rows_){nullptr}
+    , decltype(_impl_.write_hint_){nullptr}
     , decltype(_impl_.sequence_){}
     , decltype(_impl_.op_type_){}
     , /*decltype(_impl_._cached_size_)*/{}};
@@ -165,6 +394,9 @@ Mutation::Mutation(const Mutation& from)
   if (from._internal_has_rows()) {
     _this->_impl_.rows_ = new ::greptime::v1::Rows(*from._impl_.rows_);
   }
+  if (from._internal_has_write_hint()) {
+    _this->_impl_.write_hint_ = new ::greptime::v1::WriteHint(*from._impl_.write_hint_);
+  }
   ::memcpy(&_impl_.sequence_, &from._impl_.sequence_,
     static_cast<size_t>(reinterpret_cast<char*>(&_impl_.op_type_) -
     reinterpret_cast<char*>(&_impl_.sequence_)) + sizeof(_impl_.op_type_));
@@ -177,6 +409,7 @@ inline void Mutation::SharedCtor(
   (void)is_message_owned;
   new (&_impl_) Impl_{
       decltype(_impl_.rows_){nullptr}
+    , decltype(_impl_.write_hint_){nullptr}
     , decltype(_impl_.sequence_){uint64_t{0u}}
     , decltype(_impl_.op_type_){0}
     , /*decltype(_impl_._cached_size_)*/{}
@@ -195,6 +428,7 @@ Mutation::~Mutation() {
 inline void Mutation::SharedDtor() {
   GOOGLE_DCHECK(GetArenaForAllocation() == nullptr);
   if (this != internal_default_instance()) delete _impl_.rows_;
+  if (this != internal_default_instance()) delete _impl_.write_hint_;
 }
 
 void Mutation::SetCachedSize(int size) const {
@@ -211,6 +445,10 @@ void Mutation::Clear() {
     delete _impl_.rows_;
   }
   _impl_.rows_ = nullptr;
+  if (GetArenaForAllocation() == nullptr && _impl_.write_hint_ != nullptr) {
+    delete _impl_.write_hint_;
+  }
+  _impl_.write_hint_ = nullptr;
   ::memset(&_impl_.sequence_, 0, static_cast<size_t>(
       reinterpret_cast<char*>(&_impl_.op_type_) -
       reinterpret_cast<char*>(&_impl_.sequence_)) + sizeof(_impl_.op_type_));
@@ -248,6 +486,14 @@ const char* Mutation::_InternalParse(const char* ptr, ::_pbi::ParseContext* ctx)
         } else
           goto handle_unusual;
         continue;
+      // .greptime.v1.WriteHint write_hint = 4;
+      case 4:
+        if (PROTOBUF_PREDICT_TRUE(static_cast<uint8_t>(tag) == 34)) {
+          ptr = ctx->ParseMessage(_internal_mutable_write_hint(), ptr);
+          CHK_(ptr);
+        } else
+          goto handle_unusual;
+        continue;
       default:
         goto handle_unusual;
     }  // switch
@@ -297,6 +543,13 @@ uint8_t* Mutation::_InternalSerialize(
         _Internal::rows(this).GetCachedSize(), target, stream);
   }
 
+  // .greptime.v1.WriteHint write_hint = 4;
+  if (this->_internal_has_write_hint()) {
+    target = ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::
+      InternalWriteMessage(4, _Internal::write_hint(this),
+        _Internal::write_hint(this).GetCachedSize(), target, stream);
+  }
+
   if (PROTOBUF_PREDICT_FALSE(_internal_metadata_.have_unknown_fields())) {
     target = ::_pbi::WireFormat::InternalSerializeUnknownFieldsToArray(
         _internal_metadata_.unknown_fields<::PROTOBUF_NAMESPACE_ID::UnknownFieldSet>(::PROTOBUF_NAMESPACE_ID::UnknownFieldSet::default_instance), target, stream);
@@ -320,6 +573,13 @@ size_t Mutation::ByteSizeLong() const {
         *_impl_.rows_);
   }
 
+  // .greptime.v1.WriteHint write_hint = 4;
+  if (this->_internal_has_write_hint()) {
+    total_size += 1 +
+      ::PROTOBUF_NAMESPACE_ID::internal::WireFormatLite::MessageSize(
+        *_impl_.write_hint_);
+  }
+
   // uint64 sequence = 2;
   if (this->_internal_sequence() != 0) {
     total_size += ::_pbi::WireFormatLite::UInt64SizePlusOne(this->_internal_sequence());
@@ -353,6 +613,10 @@ void Mutation::MergeImpl(::PROTOBUF_NAMESPACE_ID::Message& to_msg, const ::PROTO
     _this->_internal_mutable_rows()->::greptime::v1::Rows::MergeFrom(
         from._internal_rows());
   }
+  if (from._internal_has_write_hint()) {
+    _this->_internal_mutable_write_hint()->::greptime::v1::WriteHint::MergeFrom(
+        from._internal_write_hint());
+  }
   if (from._internal_sequence() != 0) {
     _this->_internal_set_sequence(from._internal_sequence());
   }
@@ -387,7 +651,7 @@ void Mutation::InternalSwap(Mutation* other) {
 ::PROTOBUF_NAMESPACE_ID::Metadata Mutation::GetMetadata() const {
   return ::_pbi::AssignDescriptors(
       &descriptor_table_greptime_2fv1_2fwal_2eproto_getter, &descriptor_table_greptime_2fv1_2fwal_2eproto_once,
-      file_level_metadata_greptime_2fv1_2fwal_2eproto[0]);
+      file_level_metadata_greptime_2fv1_2fwal_2eproto[1]);
 }
 
 // ===================================================================
@@ -572,13 +836,17 @@ void WalEntry::InternalSwap(WalEntry* other) {
 ::PROTOBUF_NAMESPACE_ID::Metadata WalEntry::GetMetadata() const {
   return ::_pbi::AssignDescriptors(
       &descriptor_table_greptime_2fv1_2fwal_2eproto_getter, &descriptor_table_greptime_2fv1_2fwal_2eproto_once,
-      file_level_metadata_greptime_2fv1_2fwal_2eproto[1]);
+      file_level_metadata_greptime_2fv1_2fwal_2eproto[2]);
 }
 
 // @@protoc_insertion_point(namespace_scope)
 }  // namespace v1
 }  // namespace greptime
 PROTOBUF_NAMESPACE_OPEN
+template<> PROTOBUF_NOINLINE ::greptime::v1::WriteHint*
+Arena::CreateMaybeMessage< ::greptime::v1::WriteHint >(Arena* arena) {
+  return Arena::CreateMessageInternal< ::greptime::v1::WriteHint >(arena);
+}
 template<> PROTOBUF_NOINLINE ::greptime::v1::Mutation*
 Arena::CreateMaybeMessage< ::greptime::v1::Mutation >(Arena* arena) {
   return Arena::CreateMessageInternal< ::greptime::v1::Mutation >(arena);

c++/greptime/v1/wal.pb.h

@@ -54,11 +54,15 @@ extern MutationDefaultTypeInternal _Mutation_default_instance_;
 class WalEntry;
 struct WalEntryDefaultTypeInternal;
 extern WalEntryDefaultTypeInternal _WalEntry_default_instance_;
+class WriteHint;
+struct WriteHintDefaultTypeInternal;
+extern WriteHintDefaultTypeInternal _WriteHint_default_instance_;
 }  // namespace v1
 }  // namespace greptime
 PROTOBUF_NAMESPACE_OPEN
 template<> ::greptime::v1::Mutation* Arena::CreateMaybeMessage<::greptime::v1::Mutation>(Arena*);
 template<> ::greptime::v1::WalEntry* Arena::CreateMaybeMessage<::greptime::v1::WalEntry>(Arena*);
+template<> ::greptime::v1::WriteHint* Arena::CreateMaybeMessage<::greptime::v1::WriteHint>(Arena*);
 PROTOBUF_NAMESPACE_CLOSE
 namespace greptime {
 namespace v1 {
@@ -88,8 +92,181 @@ inline bool OpType_Parse(
   return ::PROTOBUF_NAMESPACE_ID::internal::ParseNamedEnum<OpType>(
     OpType_descriptor(), name, value);
 }
+enum PrimaryKeyEncoding : int {
+  DENSE = 0,
+  SPARSE = 1,
+  PrimaryKeyEncoding_INT_MIN_SENTINEL_DO_NOT_USE_ = std::numeric_limits<int32_t>::min(),
+  PrimaryKeyEncoding_INT_MAX_SENTINEL_DO_NOT_USE_ = std::numeric_limits<int32_t>::max()
+};
+bool PrimaryKeyEncoding_IsValid(int value);
+constexpr PrimaryKeyEncoding PrimaryKeyEncoding_MIN = DENSE;
+constexpr PrimaryKeyEncoding PrimaryKeyEncoding_MAX = SPARSE;
+constexpr int PrimaryKeyEncoding_ARRAYSIZE = PrimaryKeyEncoding_MAX + 1;
+
+const ::PROTOBUF_NAMESPACE_ID::EnumDescriptor* PrimaryKeyEncoding_descriptor();
+template<typename T>
+inline const std::string& PrimaryKeyEncoding_Name(T enum_t_value) {
+  static_assert(::std::is_same<T, PrimaryKeyEncoding>::value ||
+    ::std::is_integral<T>::value,
+    "Incorrect type passed to function PrimaryKeyEncoding_Name.");
+  return ::PROTOBUF_NAMESPACE_ID::internal::NameOfEnum(
+    PrimaryKeyEncoding_descriptor(), enum_t_value);
+}
+inline bool PrimaryKeyEncoding_Parse(
+    ::PROTOBUF_NAMESPACE_ID::ConstStringParam name, PrimaryKeyEncoding* value) {
+  return ::PROTOBUF_NAMESPACE_ID::internal::ParseNamedEnum<PrimaryKeyEncoding>(
+    PrimaryKeyEncoding_descriptor(), name, value);
+}
 // ===================================================================
 
+class WriteHint final :
+    public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:greptime.v1.WriteHint) */ {
+ public:
+  inline WriteHint() : WriteHint(nullptr) {}
+  ~WriteHint() override;
+  explicit PROTOBUF_CONSTEXPR WriteHint(::PROTOBUF_NAMESPACE_ID::internal::ConstantInitialized);
+
+  WriteHint(const WriteHint& from);
+  WriteHint(WriteHint&& from) noexcept
+    : WriteHint() {
+    *this = ::std::move(from);
+  }
+
+  inline WriteHint& operator=(const WriteHint& from) {
+    CopyFrom(from);
+    return *this;
+  }
+  inline WriteHint& operator=(WriteHint&& from) noexcept {
+    if (this == &from) return *this;
+    if (GetOwningArena() == from.GetOwningArena()
+  #ifdef PROTOBUF_FORCE_COPY_IN_MOVE
+        && GetOwningArena() != nullptr
+  #endif  // !PROTOBUF_FORCE_COPY_IN_MOVE
+    ) {
+      InternalSwap(&from);
+    } else {
+      CopyFrom(from);
+    }
+    return *this;
+  }
+
+  static const ::PROTOBUF_NAMESPACE_ID::Descriptor* descriptor() {
+    return GetDescriptor();
+  }
+  static const ::PROTOBUF_NAMESPACE_ID::Descriptor* GetDescriptor() {
+    return default_instance().GetMetadata().descriptor;
+  }
+  static const ::PROTOBUF_NAMESPACE_ID::Reflection* GetReflection() {
+    return default_instance().GetMetadata().reflection;
+  }
+  static const WriteHint& default_instance() {
+    return *internal_default_instance();
+  }
+  static inline const WriteHint* internal_default_instance() {
+    return reinterpret_cast<const WriteHint*>(
+               &_WriteHint_default_instance_);
+  }
+  static constexpr int kIndexInFileMessages =
+    0;
+
+  friend void swap(WriteHint& a, WriteHint& b) {
+    a.Swap(&b);
+  }
+  inline void Swap(WriteHint* other) {
+    if (other == this) return;
+  #ifdef PROTOBUF_FORCE_COPY_IN_SWAP
+    if (GetOwningArena() != nullptr &&
+        GetOwningArena() == other->GetOwningArena()) {
+   #else  // PROTOBUF_FORCE_COPY_IN_SWAP
+    if (GetOwningArena() == other->GetOwningArena()) {
+  #endif  // !PROTOBUF_FORCE_COPY_IN_SWAP
+      InternalSwap(other);
+    } else {
+      ::PROTOBUF_NAMESPACE_ID::internal::GenericSwap(this, other);
+    }
+  }
+  void UnsafeArenaSwap(WriteHint* other) {
+    if (other == this) return;
+    GOOGLE_DCHECK(GetOwningArena() == other->GetOwningArena());
+    InternalSwap(other);
+  }
+
+  // implements Message ----------------------------------------------
+
+  WriteHint* New(::PROTOBUF_NAMESPACE_ID::Arena* arena = nullptr) const final {
+    return CreateMaybeMessage<WriteHint>(arena);
+  }
+  using ::PROTOBUF_NAMESPACE_ID::Message::CopyFrom;
+  void CopyFrom(const WriteHint& from);
+  using ::PROTOBUF_NAMESPACE_ID::Message::MergeFrom;
+  void MergeFrom( const WriteHint& from) {
+    WriteHint::MergeImpl(*this, from);
+  }
+  private:
+  static void MergeImpl(::PROTOBUF_NAMESPACE_ID::Message& to_msg, const ::PROTOBUF_NAMESPACE_ID::Message& from_msg);
+  public:
+  PROTOBUF_ATTRIBUTE_REINITIALIZES void Clear() final;
+  bool IsInitialized() const final;
+
+  size_t ByteSizeLong() const final;
+  const char* _InternalParse(const char* ptr, ::PROTOBUF_NAMESPACE_ID::internal::ParseContext* ctx) final;
+  uint8_t* _InternalSerialize(
+      uint8_t* target, ::PROTOBUF_NAMESPACE_ID::io::EpsCopyOutputStream* stream) const final;
+  int GetCachedSize() const final { return _impl_._cached_size_.Get(); }
+
+  private:
+  void SharedCtor(::PROTOBUF_NAMESPACE_ID::Arena* arena, bool is_message_owned);
+  void SharedDtor();
+  void SetCachedSize(int size) const final;
+  void InternalSwap(WriteHint* other);
+
+  private:
+  friend class ::PROTOBUF_NAMESPACE_ID::internal::AnyMetadata;
+  static ::PROTOBUF_NAMESPACE_ID::StringPiece FullMessageName() {
+    return "greptime.v1.WriteHint";
+  }
+  protected:
+  explicit WriteHint(::PROTOBUF_NAMESPACE_ID::Arena* arena,
+                       bool is_message_owned = false);
+  public:
+
+  static const ClassData _class_data_;
+  const ::PROTOBUF_NAMESPACE_ID::Message::ClassData*GetClassData() const final;
+
+  ::PROTOBUF_NAMESPACE_ID::Metadata GetMetadata() const final;
+
+  // nested types ----------------------------------------------------
+
+  // accessors -------------------------------------------------------
+
+  enum : int {
+    kPrimaryKeyEncodingFieldNumber = 1,
+  };
+  // .greptime.v1.PrimaryKeyEncoding primary_key_encoding = 1;
+  void clear_primary_key_encoding();
+  ::greptime::v1::PrimaryKeyEncoding primary_key_encoding() const;
+  void set_primary_key_encoding(::greptime::v1::PrimaryKeyEncoding value);
+  private:
+  ::greptime::v1::PrimaryKeyEncoding _internal_primary_key_encoding() const;
+  void _internal_set_primary_key_encoding(::greptime::v1::PrimaryKeyEncoding value);
+  public:
+
+  // @@protoc_insertion_point(class_scope:greptime.v1.WriteHint)
+ private:
+  class _Internal;
+
+  template <typename T> friend class ::PROTOBUF_NAMESPACE_ID::Arena::InternalHelper;
+  typedef void InternalArenaConstructable_;
+  typedef void DestructorSkippable_;
+  struct Impl_ {
+    int primary_key_encoding_;
+    mutable ::PROTOBUF_NAMESPACE_ID::internal::CachedSize _cached_size_;
+  };
+  union { Impl_ _impl_; };
+  friend struct ::TableStruct_greptime_2fv1_2fwal_2eproto;
+};
+// -------------------------------------------------------------------
+
 class Mutation final :
     public ::PROTOBUF_NAMESPACE_ID::Message /* @@protoc_insertion_point(class_definition:greptime.v1.Mutation) */ {
  public:
@@ -138,7 +315,7 @@ class Mutation final :
                &_Mutation_default_instance_);
   }
   static constexpr int kIndexInFileMessages =
-    0;
+    1;
 
   friend void swap(Mutation& a, Mutation& b) {
     a.Swap(&b);
@@ -212,6 +389,7 @@ class Mutation final :
 
   enum : int {
     kRowsFieldNumber = 3,
+    kWriteHintFieldNumber = 4,
     kSequenceFieldNumber = 2,
     kOpTypeFieldNumber = 1,
   };
@@ -233,6 +411,24 @@ class Mutation final :
       ::greptime::v1::Rows* rows);
   ::greptime::v1::Rows* unsafe_arena_release_rows();
 
+  // .greptime.v1.WriteHint write_hint = 4;
+  bool has_write_hint() const;
+  private:
+  bool _internal_has_write_hint() const;
+  public:
+  void clear_write_hint();
+  const ::greptime::v1::WriteHint& write_hint() const;
+  PROTOBUF_NODISCARD ::greptime::v1::WriteHint* release_write_hint();
+  ::greptime::v1::WriteHint* mutable_write_hint();
+  void set_allocated_write_hint(::greptime::v1::WriteHint* write_hint);
+  private:
+  const ::greptime::v1::WriteHint& _internal_write_hint() const;
+  ::greptime::v1::WriteHint* _internal_mutable_write_hint();
+  public:
+  void unsafe_arena_set_allocated_write_hint(
+      ::greptime::v1::WriteHint* write_hint);
+  ::greptime::v1::WriteHint* unsafe_arena_release_write_hint();
+
   // uint64 sequence = 2;
   void clear_sequence();
   uint64_t sequence() const;
@@ -260,6 +456,7 @@ class Mutation final :
   typedef void DestructorSkippable_;
   struct Impl_ {
     ::greptime::v1::Rows* rows_;
+    ::greptime::v1::WriteHint* write_hint_;
     uint64_t sequence_;
     int op_type_;
     mutable ::PROTOBUF_NAMESPACE_ID::internal::CachedSize _cached_size_;
@@ -317,7 +514,7 @@ class WalEntry final :
                &_WalEntry_default_instance_);
   }
   static constexpr int kIndexInFileMessages =
-    1;
+    2;
 
   friend void swap(WalEntry& a, WalEntry& b) {
     a.Swap(&b);
@@ -433,6 +630,30 @@ class WalEntry final :
   #pragma GCC diagnostic push
   #pragma GCC diagnostic ignored "-Wstrict-aliasing"
 #endif  // __GNUC__
+// WriteHint
+
+// .greptime.v1.PrimaryKeyEncoding primary_key_encoding = 1;
+inline void WriteHint::clear_primary_key_encoding() {
+  _impl_.primary_key_encoding_ = 0;
+}
+inline ::greptime::v1::PrimaryKeyEncoding WriteHint::_internal_primary_key_encoding() const {
+  return static_cast< ::greptime::v1::PrimaryKeyEncoding >(_impl_.primary_key_encoding_);
+}
+inline ::greptime::v1::PrimaryKeyEncoding WriteHint::primary_key_encoding() const {
+  // @@protoc_insertion_point(field_get:greptime.v1.WriteHint.primary_key_encoding)
+  return _internal_primary_key_encoding();
+}
+inline void WriteHint::_internal_set_primary_key_encoding(::greptime::v1::PrimaryKeyEncoding value) {
+  
+  _impl_.primary_key_encoding_ = value;
+}
+inline void WriteHint::set_primary_key_encoding(::greptime::v1::PrimaryKeyEncoding value) {
+  _internal_set_primary_key_encoding(value);
+  // @@protoc_insertion_point(field_set:greptime.v1.WriteHint.primary_key_encoding)
+}
+
+// -------------------------------------------------------------------
+
 // Mutation
 
 // .greptime.v1.OpType op_type = 1;
@@ -560,6 +781,96 @@ inline void Mutation::set_allocated_rows(::greptime::v1::Rows* rows) {
   // @@protoc_insertion_point(field_set_allocated:greptime.v1.Mutation.rows)
 }
 
+// .greptime.v1.WriteHint write_hint = 4;
+inline bool Mutation::_internal_has_write_hint() const {
+  return this != internal_default_instance() && _impl_.write_hint_ != nullptr;
+}
+inline bool Mutation::has_write_hint() const {
+  return _internal_has_write_hint();
+}
+inline void Mutation::clear_write_hint() {
+  if (GetArenaForAllocation() == nullptr && _impl_.write_hint_ != nullptr) {
+    delete _impl_.write_hint_;
+  }
+  _impl_.write_hint_ = nullptr;
+}
+inline const ::greptime::v1::WriteHint& Mutation::_internal_write_hint() const {
+  const ::greptime::v1::WriteHint* p = _impl_.write_hint_;
+  return p != nullptr ? *p : reinterpret_cast<const ::greptime::v1::WriteHint&>(
+      ::greptime::v1::_WriteHint_default_instance_);
+}
+inline const ::greptime::v1::WriteHint& Mutation::write_hint() const {
+  // @@protoc_insertion_point(field_get:greptime.v1.Mutation.write_hint)
+  return _internal_write_hint();
+}
+inline void Mutation::unsafe_arena_set_allocated_write_hint(
+    ::greptime::v1::WriteHint* write_hint) {
+  if (GetArenaForAllocation() == nullptr) {
+    delete reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(_impl_.write_hint_);
+  }
+  _impl_.write_hint_ = write_hint;
+  if (write_hint) {
+    
+  } else {
+    
+  }
+  // @@protoc_insertion_point(field_unsafe_arena_set_allocated:greptime.v1.Mutation.write_hint)
+}
+inline ::greptime::v1::WriteHint* Mutation::release_write_hint() {
+  
+  ::greptime::v1::WriteHint* temp = _impl_.write_hint_;
+  _impl_.write_hint_ = nullptr;
+#ifdef PROTOBUF_FORCE_COPY_IN_RELEASE
+  auto* old =  reinterpret_cast<::PROTOBUF_NAMESPACE_ID::MessageLite*>(temp);
+  temp = ::PROTOBUF_NAMESPACE_ID::internal::DuplicateIfNonNull(temp);
+  if (GetArenaForAllocation() == nullptr) { delete old; }
+#else  // PROTOBUF_FORCE_COPY_IN_RELEASE
+  if (GetArenaForAllocation() != nullptr) {
+    temp = ::PROTOBUF_NAMESPACE_ID::internal::DuplicateIfNonNull(temp);
+  }
+#endif  // !PROTOBUF_FORCE_COPY_IN_RELEASE
+  return temp;
+}
+inline ::greptime::v1::WriteHint* Mutation::unsafe_arena_release_write_hint() {
+  // @@protoc_insertion_point(field_release:greptime.v1.Mutation.write_hint)
+  
+  ::greptime::v1::WriteHint* temp = _impl_.write_hint_;
+  _impl_.write_hint_ = nullptr;
+  return temp;
+}
+inline ::greptime::v1::WriteHint* Mutation::_internal_mutable_write_hint() {
+  
+  if (_impl_.write_hint_ == nullptr) {
+    auto* p = CreateMaybeMessage<::greptime::v1::WriteHint>(GetArenaForAllocation());
+    _impl_.write_hint_ = p;
+  }
+  return _impl_.write_hint_;
+}
+inline ::greptime::v1::WriteHint* Mutation::mutable_write_hint() {
+  ::greptime::v1::WriteHint* _msg = _internal_mutable_write_hint();
+  // @@protoc_insertion_point(field_mutable:greptime.v1.Mutation.write_hint)
+  return _msg;
+}
+inline void Mutation::set_allocated_write_hint(::greptime::v1::WriteHint* write_hint) {
+  ::PROTOBUF_NAMESPACE_ID::Arena* message_arena = GetArenaForAllocation();
+  if (message_arena == nullptr) {
+    delete _impl_.write_hint_;
+  }
+  if (write_hint) {
+    ::PROTOBUF_NAMESPACE_ID::Arena* submessage_arena =
+        ::PROTOBUF_NAMESPACE_ID::Arena::InternalGetOwningArena(write_hint);
+    if (message_arena != submessage_arena) {
+      write_hint = ::PROTOBUF_NAMESPACE_ID::internal::GetOwnedMessage(
+          message_arena, write_hint, submessage_arena);
+    }
+    
+  } else {
+    
+  }
+  _impl_.write_hint_ = write_hint;
+  // @@protoc_insertion_point(field_set_allocated:greptime.v1.Mutation.write_hint)
+}
+
 // -------------------------------------------------------------------
 
 // WalEntry
@@ -609,6 +920,8 @@ WalEntry::mutations() const {
 #endif  // __GNUC__
 // -------------------------------------------------------------------
 
+// -------------------------------------------------------------------
+
 
 // @@protoc_insertion_point(namespace_scope)
 
@@ -622,6 +935,11 @@ template <>
 inline const EnumDescriptor* GetEnumDescriptor< ::greptime::v1::OpType>() {
   return ::greptime::v1::OpType_descriptor();
 }
+template <> struct is_proto_enum< ::greptime::v1::PrimaryKeyEncoding> : ::std::true_type {};
+template <>
+inline const EnumDescriptor* GetEnumDescriptor< ::greptime::v1::PrimaryKeyEncoding>() {
+  return ::greptime::v1::PrimaryKeyEncoding_descriptor();
+}
 
 PROTOBUF_NAMESPACE_CLOSE
 

go/greptime/v1/wal.pb.go

@@ -83,6 +83,101 @@ func (OpType) EnumDescriptor() ([]byte, []int) {
 	return file_greptime_v1_wal_proto_rawDescGZIP(), []int{0}
 }
 
+// Encoding of primary key.
+type PrimaryKeyEncoding int32
+
+const (
+	PrimaryKeyEncoding_DENSE  PrimaryKeyEncoding = 0
+	PrimaryKeyEncoding_SPARSE PrimaryKeyEncoding = 1
+)
+
+// Enum value maps for PrimaryKeyEncoding.
+var (
+	PrimaryKeyEncoding_name = map[int32]string{
+		0: "DENSE",
+		1: "SPARSE",
+	}
+	PrimaryKeyEncoding_value = map[string]int32{
+		"DENSE":  0,
+		"SPARSE": 1,
+	}
+)
+
+func (x PrimaryKeyEncoding) Enum() *PrimaryKeyEncoding {
+	p := new(PrimaryKeyEncoding)
+	*p = x
+	return p
+}
+
+func (x PrimaryKeyEncoding) String() string {
+	return protoimpl.X.EnumStringOf(x.Descriptor(), protoreflect.EnumNumber(x))
+}
+
+func (PrimaryKeyEncoding) Descriptor() protoreflect.EnumDescriptor {
+	return file_greptime_v1_wal_proto_enumTypes[1].Descriptor()
+}
+
+func (PrimaryKeyEncoding) Type() protoreflect.EnumType {
+	return &file_greptime_v1_wal_proto_enumTypes[1]
+}
+
+func (x PrimaryKeyEncoding) Number() protoreflect.EnumNumber {
+	return protoreflect.EnumNumber(x)
+}
+
+// Deprecated: Use PrimaryKeyEncoding.Descriptor instead.
+func (PrimaryKeyEncoding) EnumDescriptor() ([]byte, []int) {
+	return file_greptime_v1_wal_proto_rawDescGZIP(), []int{1}
+}
+
+// Write hint of the mutation.
+type WriteHint struct {
+	state         protoimpl.MessageState
+	sizeCache     protoimpl.SizeCache
+	unknownFields protoimpl.UnknownFields
+
+	PrimaryKeyEncoding PrimaryKeyEncoding `protobuf:"varint,1,opt,name=primary_key_encoding,json=primaryKeyEncoding,proto3,enum=greptime.v1.PrimaryKeyEncoding" json:"primary_key_encoding,omitempty"`
+}
+
+func (x *WriteHint) Reset() {
+	*x = WriteHint{}
+	if protoimpl.UnsafeEnabled {
+		mi := &file_greptime_v1_wal_proto_msgTypes[0]
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		ms.StoreMessageInfo(mi)
+	}
+}
+
+func (x *WriteHint) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*WriteHint) ProtoMessage() {}
+
+func (x *WriteHint) ProtoReflect() protoreflect.Message {
+	mi := &file_greptime_v1_wal_proto_msgTypes[0]
+	if protoimpl.UnsafeEnabled && x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use WriteHint.ProtoReflect.Descriptor instead.
+func (*WriteHint) Descriptor() ([]byte, []int) {
+	return file_greptime_v1_wal_proto_rawDescGZIP(), []int{0}
+}
+
+func (x *WriteHint) GetPrimaryKeyEncoding() PrimaryKeyEncoding {
+	if x != nil {
+		return x.PrimaryKeyEncoding
+	}
+	return PrimaryKeyEncoding_DENSE
+}
+
 // Mutation contains updates to a set of rows.
 type Mutation struct {
 	state         protoimpl.MessageState
@@ -95,12 +190,14 @@ type Mutation struct {
 	Sequence uint64 `protobuf:"varint,2,opt,name=sequence,proto3" json:"sequence,omitempty"`
 	// Row updates to write to the WAL.
 	Rows *Rows `protobuf:"bytes,3,opt,name=rows,proto3" json:"rows,omitempty"`
+	// Write hint of the mutation.
+	WriteHint *WriteHint `protobuf:"bytes,4,opt,name=write_hint,json=writeHint,proto3" json:"write_hint,omitempty"`
 }
 
 func (x *Mutation) Reset() {
 	*x = Mutation{}
 	if protoimpl.UnsafeEnabled {
-		mi := &file_greptime_v1_wal_proto_msgTypes[0]
+		mi := &file_greptime_v1_wal_proto_msgTypes[1]
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		ms.StoreMessageInfo(mi)
 	}
@@ -113,7 +210,7 @@ func (x *Mutation) String() string {
 func (*Mutation) ProtoMessage() {}
 
 func (x *Mutation) ProtoReflect() protoreflect.Message {
-	mi := &file_greptime_v1_wal_proto_msgTypes[0]
+	mi := &file_greptime_v1_wal_proto_msgTypes[1]
 	if protoimpl.UnsafeEnabled && x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -126,7 +223,7 @@ func (x *Mutation) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use Mutation.ProtoReflect.Descriptor instead.
 func (*Mutation) Descriptor() ([]byte, []int) {
-	return file_greptime_v1_wal_proto_rawDescGZIP(), []int{0}
+	return file_greptime_v1_wal_proto_rawDescGZIP(), []int{1}
 }
 
 func (x *Mutation) GetOpType() OpType {
@@ -150,6 +247,13 @@ func (x *Mutation) GetRows() *Rows {
 	return nil
 }
 
+func (x *Mutation) GetWriteHint() *WriteHint {
+	if x != nil {
+		return x.WriteHint
+	}
+	return nil
+}
+
 // A WAL entry contains a list of mutations for a region to write.
 type WalEntry struct {
 	state         protoimpl.MessageState
@@ -163,7 +267,7 @@ type WalEntry struct {
 func (x *WalEntry) Reset() {
 	*x = WalEntry{}
 	if protoimpl.UnsafeEnabled {
-		mi := &file_greptime_v1_wal_proto_msgTypes[1]
+		mi := &file_greptime_v1_wal_proto_msgTypes[2]
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		ms.StoreMessageInfo(mi)
 	}
@@ -176,7 +280,7 @@ func (x *WalEntry) String() string {
 func (*WalEntry) ProtoMessage() {}
 
 func (x *WalEntry) ProtoReflect() protoreflect.Message {
-	mi := &file_greptime_v1_wal_proto_msgTypes[1]
+	mi := &file_greptime_v1_wal_proto_msgTypes[2]
 	if protoimpl.UnsafeEnabled && x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -189,7 +293,7 @@ func (x *WalEntry) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use WalEntry.ProtoReflect.Descriptor instead.
 func (*WalEntry) Descriptor() ([]byte, []int) {
-	return file_greptime_v1_wal_proto_rawDescGZIP(), []int{1}
+	return file_greptime_v1_wal_proto_rawDescGZIP(), []int{2}
 }
 
 func (x *WalEntry) GetMutations() []*Mutation {
@@ -205,25 +309,37 @@ var file_greptime_v1_wal_proto_rawDesc = []byte{
 	0x0a, 0x15, 0x67, 0x72, 0x65, 0x70, 0x74, 0x69, 0x6d, 0x65, 0x2f, 0x76, 0x31, 0x2f, 0x77, 0x61,
 	0x6c, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x12, 0x0b, 0x67, 0x72, 0x65, 0x70, 0x74, 0x69, 0x6d,
 	0x65, 0x2e, 0x76, 0x31, 0x1a, 0x15, 0x67, 0x72, 0x65, 0x70, 0x74, 0x69, 0x6d, 0x65, 0x2f, 0x76,
-	0x31, 0x2f, 0x72, 0x6f, 0x77, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x22, 0x7b, 0x0a, 0x08, 0x4d,
+	0x31, 0x2f, 0x72, 0x6f, 0x77, 0x2e, 0x70, 0x72, 0x6f, 0x74, 0x6f, 0x22, 0x5e, 0x0a, 0x09, 0x57,
-	0x75, 0x74, 0x61, 0x74, 0x69, 0x6f, 0x6e, 0x12, 0x2c, 0x0a, 0x07, 0x6f, 0x70, 0x5f, 0x74, 0x79,
+	0x72, 0x69, 0x74, 0x65, 0x48, 0x69, 0x6e, 0x74, 0x12, 0x51, 0x0a, 0x14, 0x70, 0x72, 0x69, 0x6d,
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 }
 
 var (
@@ -238,23 +354,27 @@ func file_greptime_v1_wal_proto_rawDescGZIP() []byte {
 	return file_greptime_v1_wal_proto_rawDescData
 }
 
-var file_greptime_v1_wal_proto_enumTypes = make([]protoimpl.EnumInfo, 1)
+var file_greptime_v1_wal_proto_enumTypes = make([]protoimpl.EnumInfo, 2)
-var file_greptime_v1_wal_proto_msgTypes = make([]protoimpl.MessageInfo, 2)
+var file_greptime_v1_wal_proto_msgTypes = make([]protoimpl.MessageInfo, 3)
 var file_greptime_v1_wal_proto_goTypes = []interface{}{
 	(OpType)(0),             // 0: greptime.v1.OpType
-	(*Mutation)(nil), // 1: greptime.v1.Mutation
+	(PrimaryKeyEncoding)(0), // 1: greptime.v1.PrimaryKeyEncoding
-	(*WalEntry)(nil), // 2: greptime.v1.WalEntry
+	(*WriteHint)(nil),       // 2: greptime.v1.WriteHint
-	(*Rows)(nil),     // 3: greptime.v1.Rows
+	(*Mutation)(nil),        // 3: greptime.v1.Mutation
+	(*WalEntry)(nil),        // 4: greptime.v1.WalEntry
+	(*Rows)(nil),            // 5: greptime.v1.Rows
 }
 var file_greptime_v1_wal_proto_depIdxs = []int32{
-	0, // 0: greptime.v1.Mutation.op_type:type_name -> greptime.v1.OpType
+	1, // 0: greptime.v1.WriteHint.primary_key_encoding:type_name -> greptime.v1.PrimaryKeyEncoding
-	3, // 1: greptime.v1.Mutation.rows:type_name -> greptime.v1.Rows
+	0, // 1: greptime.v1.Mutation.op_type:type_name -> greptime.v1.OpType
-	1, // 2: greptime.v1.WalEntry.mutations:type_name -> greptime.v1.Mutation
+	5, // 2: greptime.v1.Mutation.rows:type_name -> greptime.v1.Rows
-	3, // [3:3] is the sub-list for method output_type
+	2, // 3: greptime.v1.Mutation.write_hint:type_name -> greptime.v1.WriteHint
-	3, // [3:3] is the sub-list for method input_type
+	3, // 4: greptime.v1.WalEntry.mutations:type_name -> greptime.v1.Mutation
-	3, // [3:3] is the sub-list for extension type_name
+	5, // [5:5] is the sub-list for method output_type
-	3, // [3:3] is the sub-list for extension extendee
+	5, // [5:5] is the sub-list for method input_type
-	0, // [0:3] is the sub-list for field type_name
+	5, // [5:5] is the sub-list for extension type_name
+	5, // [5:5] is the sub-list for extension extendee
+	0, // [0:5] is the sub-list for field type_name
 }
 
 func init() { file_greptime_v1_wal_proto_init() }
@@ -265,7 +385,7 @@ func file_greptime_v1_wal_proto_init() {
 	file_greptime_v1_row_proto_init()
 	if !protoimpl.UnsafeEnabled {
 		file_greptime_v1_wal_proto_msgTypes[0].Exporter = func(v interface{}, i int) interface{} {
-			switch v := v.(*Mutation); i {
+			switch v := v.(*WriteHint); i {
 			case 0:
 				return &v.state
 			case 1:
@@ -277,6 +397,18 @@ func file_greptime_v1_wal_proto_init() {
 			}
 		}
 		file_greptime_v1_wal_proto_msgTypes[1].Exporter = func(v interface{}, i int) interface{} {
+			switch v := v.(*Mutation); i {
+			case 0:
+				return &v.state
+			case 1:
+				return &v.sizeCache
+			case 2:
+				return &v.unknownFields
+			default:
+				return nil
+			}
+		}
+		file_greptime_v1_wal_proto_msgTypes[2].Exporter = func(v interface{}, i int) interface{} {
 			switch v := v.(*WalEntry); i {
 			case 0:
 				return &v.state
@@ -294,8 +426,8 @@ func file_greptime_v1_wal_proto_init() {
 		File: protoimpl.DescBuilder{
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: file_greptime_v1_wal_proto_rawDesc,
-			NumEnums:      1,
+			NumEnums:      2,
-			NumMessages:   2,
+			NumMessages:   3,
 			NumExtensions: 0,
 			NumServices:   0,
 		},

proto/greptime/v1/wal.proto

@@ -28,6 +28,17 @@ enum OpType {
   PUT = 1;
 }
 
+// Encoding of primary key.
+enum PrimaryKeyEncoding {
+  DENSE = 0;
+  SPARSE = 1;
+}
+
+// Write hint of the mutation.
+message WriteHint {
+  PrimaryKeyEncoding primary_key_encoding = 1;
+}
+
 // Mutation contains updates to a set of rows.
 message Mutation {
   // Type of this mutation.
@@ -36,6 +47,8 @@ message Mutation {
   uint64 sequence = 2;
   // Row updates to write to the WAL.
   Rows rows = 3;
+  // Write hint of the mutation.
+  WriteHint write_hint = 4;
 }
 
 // A WAL entry contains a list of mutations for a region to write.