diff --git a/mittest/mtlenv/storage/blocksstable/ob_index_block_data_prepare.h b/mittest/mtlenv/storage/blocksstable/ob_index_block_data_prepare.h
index 6c56d8831b..48306de839 100644
--- a/mittest/mtlenv/storage/blocksstable/ob_index_block_data_prepare.h
+++ b/mittest/mtlenv/storage/blocksstable/ob_index_block_data_prepare.h
@@ -438,7 +438,7 @@ void TestIndexBlockDataPrepare::prepare_data()
   ObIndexTreeRootBlockDesc root_desc;
   root_desc = res.root_desc_;
   ASSERT_TRUE(root_desc.is_valid());
-  ObRowStoreType root_row_store_type = root_desc.row_type_;
+  ObRowStoreType root_row_store_type = res.root_row_store_type_;
 
   char *root_buf = nullptr;
   int64_t root_size = 0;
diff --git a/src/storage/blocksstable/ob_index_block_builder.cpp b/src/storage/blocksstable/ob_index_block_builder.cpp
index 9df90f92c6..9608beed4e 100644
--- a/src/storage/blocksstable/ob_index_block_builder.cpp
+++ b/src/storage/blocksstable/ob_index_block_builder.cpp
@@ -28,83 +28,11 @@ using namespace common;
 using namespace storage;
 namespace blocksstable
 {
-
-DEFINE_SERIALIZE(ObIndexTreeRootBlockDesc)
-{
-  int ret = OB_SUCCESS;
-  int64_t new_pos = pos;
-  const int64_t serialize_size = get_serialize_size();
-  if (OB_ISNULL(buf) || OB_UNLIKELY(buf_len <= 0 || pos < 0 || serialize_size > buf_len - pos)) {
-    ret = OB_INVALID_ARGUMENT;
-    STORAGE_LOG(WARN, "invalid argument", K(ret), KP(buf), K(buf_len), K(pos), K(serialize_size));
-  } else if (OB_FAIL(serialization::encode_vi64(buf, buf_len, new_pos, UNIS_VERSION))) {
-    STORAGE_LOG(WARN, "fail to serialize UNIS_VSERSION", K(ret), K(buf_len), K(new_pos));
-  } else if (OB_FAIL(addr_.serialize(buf, buf_len, new_pos))) {
-    STORAGE_LOG(WARN, "failed to serialize addr", K(ret), K(buf_len), K(new_pos));
-  } else if (OB_FAIL(serialization::encode_i8(buf, buf_len, new_pos, row_type_))) {
-    STORAGE_LOG(WARN, "failed to serialize row_type", K(ret), K(buf_len), K(new_pos));
-  } else if (OB_FAIL(serialization::encode_i64(buf, buf_len, new_pos, height_))) {
-    STORAGE_LOG(WARN, "failed to serialize height", K(ret), K(buf_len), K(new_pos));
-  } else if (addr_.is_memory()
-             && OB_FAIL(serialization::encode_vstr(buf, buf_len, new_pos, buf_, addr_.size()))) {
-    STORAGE_LOG(WARN, "failed to serialize buf_", K(ret), K(buf_len), K(new_pos), K(addr_));
-  } else {
-    pos = new_pos;
-  }
-  return ret;
-}
-
-DEFINE_DESERIALIZE(ObIndexTreeRootBlockDesc)
-{
-  int ret = OB_SUCCESS;
-  int64_t len = 0;
-  int64_t version = 0;
-  int64_t new_pos = pos;
-  if (OB_ISNULL(buf) || OB_UNLIKELY(data_len <= 0 || pos < 0)) {
-    ret = OB_INVALID_ARGUMENT;
-    STORAGE_LOG(WARN, "invalid argument", K(ret), KP(buf), K(data_len), K(pos));
-  } else if (OB_FAIL(serialization::decode_vi64(buf, data_len, new_pos, &version))) {
-    STORAGE_LOG(WARN, "deserialize version failed.", KR(ret), K(data_len), K(new_pos));
-  } else if (version != UNIS_VERSION) {
-    ret = OB_VERSION_NOT_MATCH;
-    STORAGE_LOG(WARN, "deserialize version failed.", KR(ret), K(version));
-  } else if (OB_FAIL(addr_.deserialize(buf, data_len, new_pos))) {
-    STORAGE_LOG(WARN, "failed to deserialize addr", K(ret), K(data_len), K(new_pos));
-  } else if (OB_FAIL(serialization::decode_i8(buf, data_len, new_pos, (int8_t *)(&row_type_)))) {
-    STORAGE_LOG(WARN, "failed to deserialize row_type", K(ret), K(data_len), K(new_pos));
-  } else if (OB_FAIL(serialization::decode_i64(buf, data_len, new_pos, &height_))) {
-    STORAGE_LOG(WARN, "failed to deserialize height", K(ret), K(data_len), K(new_pos));
-  } else if (addr_.is_memory()) {
-    buf_ = const_cast<char *>(serialization::decode_vstr(buf, data_len, new_pos, &len));
-    if (OB_ISNULL(buf_)) {
-      ret = OB_ERROR;
-      STORAGE_LOG(WARN, "failed to deserialize buf_", K(ret), K(data_len), K(new_pos), K(addr_), K(buf_), K(buf), K(len));
-    }
-  }
-  if (OB_SUCC(ret)) {
-    pos = new_pos;
-  }
-  return ret;
-}
-
-DEFINE_GET_SERIALIZE_SIZE(ObIndexTreeRootBlockDesc)
-{
-  int64_t serialize_size = addr_.get_serialize_size()
-                           + serialization::encoded_length_i8(row_type_)
-                           + serialization::encoded_length_i64(height_)
-                           + serialization::encoded_length_vi64(UNIS_VERSION);
-  if (addr_.is_memory()) {
-    serialize_size += serialization::encoded_length_vstr(addr_.size());
-  }
-  return serialize_size;
-}
-
 bool ObIndexTreeRootBlockDesc::is_valid() const
 {
   return is_empty()
       || (addr_.is_valid()
         && (is_mem_type() ? (buf_ != nullptr) : (buf_ == nullptr))
-        && row_type_ < common::ObRowStoreType::MAX_ROW_STORE
         && height_ > 0);
 }
 
@@ -112,7 +40,6 @@ void ObIndexTreeRootBlockDesc::set_empty()
 {
   addr_.set_none_addr();
   buf_ = nullptr;
-  row_type_ = FLAT_ROW_STORE;
   height_ = 0;
   is_meta_root_ = false;
 }
@@ -147,7 +74,8 @@ ObSSTableMergeRes::ObSSTableMergeRes()
     encrypt_id_(0),
     master_key_id_(0),
     nested_offset_(0),
-    nested_size_(0)
+    nested_size_(0),
+    root_row_store_type_(ObRowStoreType::MAX_ROW_STORE)
 {
   MEMSET(encrypt_key_, 0, share::OB_MAX_TABLESPACE_ENCRYPT_KEY_LENGTH);
 }
@@ -175,9 +103,25 @@ void ObSSTableMergeRes::reset()
     }
   }
   other_block_ids_.destroy();
+  index_blocks_cnt_ = 0;
+  data_blocks_cnt_ = 0;
   micro_block_cnt_ = 0;
-  nested_size_ = 0;
+  data_column_cnt_ = 0;
+  row_count_ = 0;
+  max_merged_trans_version_ = 0;
+  contain_uncommitted_row_ = false;
+  occupy_size_ = 0;
+  original_size_ = 0;
+  data_checksum_ = 0;
+  use_old_macro_block_count_ = 0;
+  data_column_checksums_.reset();
+  data_default_column_rows_cnt_.reset();
+  compressor_type_ = ObCompressorType::INVALID_COMPRESSOR;
+  encrypt_id_ = 0;
+  master_key_id_ = 0;
   nested_offset_ = 0;
+  nested_size_ = 0;
+  root_row_store_type_ = ObRowStoreType::MAX_ROW_STORE;
 }
 
 bool ObSSTableMergeRes::is_valid() const
@@ -189,7 +133,8 @@ bool ObSSTableMergeRes::is_valid() const
       && micro_block_cnt_ >= 0
       && data_column_cnt_ > 0
       && nested_offset_ >= 0
-      && nested_size_ >= 0;
+      && nested_size_ >= 0
+      && root_row_store_type_ < ObRowStoreType::MAX_ROW_STORE;
 }
 
 int ObSSTableMergeRes::assign(const ObSSTableMergeRes &src)
@@ -219,6 +164,7 @@ int ObSSTableMergeRes::assign(const ObSSTableMergeRes &src)
     master_key_id_ = src.master_key_id_;
     nested_size_ = src.nested_size_;
     nested_offset_ = src.nested_offset_;
+    root_row_store_type_ = src.root_row_store_type_;
     MEMCPY(encrypt_key_, src.encrypt_key_, sizeof(encrypt_key_));
 
     if (OB_FAIL(data_block_ids_.reserve(src.data_block_ids_.count()))) {
@@ -915,6 +861,7 @@ int ObSSTableIndexBuilder::close(const int64_t column_cnt, ObSSTableMergeRes &re
   }
 
   if (OB_SUCC(ret) && OB_LIKELY(!is_closed_)) {
+    res.root_row_store_type_ = index_store_desc_.row_store_type_;
     res.compressor_type_ = index_store_desc_.compressor_type_;
     res.encrypt_id_ = index_store_desc_.encrypt_id_;
     MEMCPY(res.encrypt_key_, index_store_desc_.encrypt_key_,
@@ -1309,7 +1256,6 @@ int ObBaseIndexBlockBuilder::close(ObIAllocator &allocator, ObIndexTreeInfo &tre
     STORAGE_LOG(WARN, "unexpected null root builder", K(ret), K(root_builder));
   } else {
     ObMetaDiskAddr &root_addr = desc.addr_;
-    desc.row_type_ = index_store_desc_->row_store_type_;
     desc.height_ = root_builder->level_ + 1;
     ObMicroBlockDesc micro_block_desc;
     ObIMicroBlockWriter *micro_writer = root_builder->micro_writer_;
@@ -2301,7 +2247,6 @@ int ObMetaIndexBlockBuilder::build_single_node_tree(
 {
   int ret = OB_SUCCESS;
   ObMetaDiskAddr &root_addr = block_desc.addr_;
-  block_desc.row_type_ = index_store_desc_->row_store_type_;
   block_desc.height_ = 1;
   char *&root_buf = block_desc.buf_;
   const int64_t buf_size = micro_block_desc.buf_size_ + micro_block_desc.header_->header_size_;
diff --git a/src/storage/blocksstable/ob_index_block_builder.h b/src/storage/blocksstable/ob_index_block_builder.h
index 170c735278..8bdd1a7594 100644
--- a/src/storage/blocksstable/ob_index_block_builder.h
+++ b/src/storage/blocksstable/ob_index_block_builder.h
@@ -126,12 +126,10 @@ public:
 
 struct ObIndexTreeRootBlockDesc final
 {
-  OB_UNIS_VERSION(1);
 public:
   ObIndexTreeRootBlockDesc()
     :addr_(),
      buf_(nullptr),
-     row_type_(common::ObRowStoreType::MAX_ROW_STORE),
      height_(0),
      is_meta_root_(false) {}
   ~ObIndexTreeRootBlockDesc() = default;
@@ -140,11 +138,10 @@ public:
   void set_empty();
   bool is_mem_type() const { return addr_.is_memory(); }
   bool is_file_type() const { return addr_.is_file(); }
-  TO_STRING_KV(K_(addr), KP_(buf), K_(row_type), K_(height));
+  TO_STRING_KV(K_(addr), KP_(buf), K_(height), K_(is_meta_root));
 public:
   storage::ObMetaDiskAddr addr_;
   char *buf_;
-  ObRowStoreType row_type_;
   int64_t height_;
   bool is_meta_root_;
 };
@@ -201,8 +198,8 @@ public:
       K_(data_column_cnt), K_(data_column_checksums), K_(data_default_column_rows_cnt),
       K_(row_count), K_(max_merged_trans_version), K_(contain_uncommitted_row),
       K_(occupy_size), K_(original_size), K_(data_checksum), K_(use_old_macro_block_count),
-      K_(compressor_type), K_(encrypt_id),
-      K_(master_key_id), KPHEX_(encrypt_key, sizeof(encrypt_key_)));
+      K_(compressor_type), K_(root_row_store_type), K_(nested_offset), K_(nested_size),
+      K_(encrypt_id), K_(master_key_id), KPHEX_(encrypt_key, sizeof(encrypt_key_)));
 public:
   ObIndexTreeRootBlockDesc root_desc_;
   ObIndexTreeRootBlockDesc data_root_desc_;
@@ -226,6 +223,7 @@ public:
   int64_t master_key_id_;
   int64_t nested_offset_;
   int64_t nested_size_;
+  ObRowStoreType root_row_store_type_;
   char encrypt_key_[share::OB_MAX_TABLESPACE_ENCRYPT_KEY_LENGTH];
   DISALLOW_COPY_AND_ASSIGN(ObSSTableMergeRes);
 };
diff --git a/src/storage/blocksstable/ob_shared_macro_block_manager.cpp b/src/storage/blocksstable/ob_shared_macro_block_manager.cpp
index a33f85fa27..6e12ef8719 100644
--- a/src/storage/blocksstable/ob_shared_macro_block_manager.cpp
+++ b/src/storage/blocksstable/ob_shared_macro_block_manager.cpp
@@ -643,7 +643,7 @@ int ObSharedMacroBlockMgr::create_new_sstable(
       param.root_block_addr_, param.root_block_data_);
   ObSSTableMergeRes::fill_addr_and_data(res.data_root_desc_,
       param.data_block_macro_meta_addr_, param.data_block_macro_meta_);
-  param.root_row_store_type_ = res.root_desc_.row_type_;
+  param.root_row_store_type_ = res.root_row_store_type_;
   param.data_index_tree_height_ = res.root_desc_.height_;
   param.index_blocks_cnt_ = res.index_blocks_cnt_;
   param.data_blocks_cnt_ = res.data_blocks_cnt_;
diff --git a/src/storage/compaction/ob_tablet_merge_ctx.cpp b/src/storage/compaction/ob_tablet_merge_ctx.cpp
index 2d81b4fc26..2f00e51147 100644
--- a/src/storage/compaction/ob_tablet_merge_ctx.cpp
+++ b/src/storage/compaction/ob_tablet_merge_ctx.cpp
@@ -220,7 +220,7 @@ int ObTabletMergeInfo::build_create_sstable_param(const ObTabletMergeCtx &ctx,
     ObSSTableMergeRes::fill_addr_and_data(res.data_root_desc_,
         param.data_block_macro_meta_addr_, param.data_block_macro_meta_);
     param.is_meta_root_ = res.data_root_desc_.is_meta_root_;
-    param.root_row_store_type_ = res.root_desc_.row_type_;
+    param.root_row_store_type_ = res.root_row_store_type_;
     param.data_index_tree_height_ = res.root_desc_.height_;
     param.index_blocks_cnt_ = res.index_blocks_cnt_;
     param.data_blocks_cnt_ = res.data_blocks_cnt_;
diff --git a/src/storage/ddl/ob_ddl_merge_task.cpp b/src/storage/ddl/ob_ddl_merge_task.cpp
index d234052682..c2957f0356 100644
--- a/src/storage/ddl/ob_ddl_merge_task.cpp
+++ b/src/storage/ddl/ob_ddl_merge_task.cpp
@@ -677,7 +677,7 @@ int ObTabletDDLUtil::create_ddl_sstable(ObSSTableIndexBuilder *sstable_index_bui
         ObSSTableMergeRes::fill_addr_and_data(res.data_root_desc_,
             param.data_block_macro_meta_addr_, param.data_block_macro_meta_);
         param.is_meta_root_ = res.data_root_desc_.is_meta_root_;
-        param.root_row_store_type_ = res.root_desc_.row_type_;
+        param.root_row_store_type_ = res.root_row_store_type_;
         param.data_index_tree_height_ = res.root_desc_.height_;
         param.index_blocks_cnt_ = res.index_blocks_cnt_;
         param.data_blocks_cnt_ = res.data_blocks_cnt_;
diff --git a/src/storage/high_availability/ob_physical_copy_task.cpp b/src/storage/high_availability/ob_physical_copy_task.cpp
index 6bde355a70..aab8390cb2 100644
--- a/src/storage/high_availability/ob_physical_copy_task.cpp
+++ b/src/storage/high_availability/ob_physical_copy_task.cpp
@@ -952,7 +952,7 @@ int ObPhysicalCopyFinishTask::build_create_sstable_param_(
     ObSSTableMergeRes::fill_addr_and_data(res.data_root_desc_,
         param.data_block_macro_meta_addr_, param.data_block_macro_meta_);
     param.is_meta_root_ = res.data_root_desc_.is_meta_root_;
-    param.root_row_store_type_ = res.root_desc_.row_type_;
+    param.root_row_store_type_ = res.root_row_store_type_;
     param.data_index_tree_height_ = res.root_desc_.height_;
     param.index_blocks_cnt_ = res.index_blocks_cnt_;
     param.data_blocks_cnt_ = res.data_blocks_cnt_;
diff --git a/unittest/storage/blocksstable/ob_multi_version_sstable_test.h b/unittest/storage/blocksstable/ob_multi_version_sstable_test.h
index c513f1f474..12f47f81ee 100644
--- a/unittest/storage/blocksstable/ob_multi_version_sstable_test.h
+++ b/unittest/storage/blocksstable/ob_multi_version_sstable_test.h
@@ -537,7 +537,7 @@ void ObMultiVersionSSTableTest::prepare_data_end(
   ObSSTableMergeRes::fill_addr_and_data(res.data_root_desc_,
                                         param.data_block_macro_meta_addr_, param.data_block_macro_meta_);
   param.is_meta_root_ = res.data_root_desc_.is_meta_root_;
-  param.root_row_store_type_ = res.root_desc_.row_type_;
+  param.root_row_store_type_ = res.root_row_store_type_;
   param.data_index_tree_height_ = res.root_desc_.height_;
   param.index_blocks_cnt_ = res.index_blocks_cnt_;
   param.data_blocks_cnt_ = res.data_blocks_cnt_;