diff --git a/src/dataman/RowReader.cpp b/src/dataman/RowReader.cpp
index 0bc5a731138..e4db5d4f9e2 100644
--- a/src/dataman/RowReader.cpp
+++ b/src/dataman/RowReader.cpp
@@ -113,67 +113,60 @@ RowReader::Iterator::operator bool() const {
  * class RowReader
  *
  ********************************************/
-// static
-std::unique_ptr<RowReader> RowReader::getTagPropReader(
+RowReader RowReader::getTagPropReader(
         meta::SchemaManager* schemaMan,
         folly::StringPiece row,
         GraphSpaceID space,
         TagID tag) {
     if (schemaMan == nullptr) {
         LOG(ERROR) << "schemaMan should not be nullptr!";
-        return nullptr;
+        return RowReader();
     }
     int32_t ver = getSchemaVer(row);
     if (ver >= 0) {
         auto schema = schemaMan->getTagSchema(space, tag, ver);
         if (schema == nullptr) {
-            return nullptr;
+            return RowReader();
         }
-        return std::unique_ptr<RowReader>(new RowReader(
-            row,
-            schema));
+        return RowReader(row, schema);
     } else {
         LOG(WARNING) << "Invalid schema version in the row data!";
-        return nullptr;
+        return RowReader();
     }
 }
 
-
 // static
-std::unique_ptr<RowReader> RowReader::getEdgePropReader(
-        meta::SchemaManager* schemaMan,
-        folly::StringPiece row,
-        GraphSpaceID space,
-        EdgeType edge) {
+RowReader RowReader::getEdgePropReader(
+    meta::SchemaManager* schemaMan,
+    folly::StringPiece row,
+    GraphSpaceID space,
+    EdgeType edge) {
     if (schemaMan == nullptr) {
         LOG(ERROR) << "schemaMan should not be nullptr!";
-        return nullptr;
+        return RowReader();
     }
     int32_t ver = getSchemaVer(row);
     if (ver >= 0) {
         auto schema = schemaMan->getEdgeSchema(space, edge, ver);
         if (schema == nullptr) {
-            return nullptr;
+            return RowReader();
         }
-        return std::unique_ptr<RowReader>(new RowReader(
-            row,
-            schema));
+        return RowReader(row, schema);
     } else {
         LOG(WARNING) << "Invalid schema version in the row data!";
-        return nullptr;
+        return RowReader();
     }
 }
 
 // static
-std::unique_ptr<RowReader> RowReader::getRowReader(
-        folly::StringPiece row,
-        std::shared_ptr<const meta::SchemaProviderIf> schema) {
+RowReader RowReader::getRowReader(
+    folly::StringPiece row,
+    std::shared_ptr<const meta::SchemaProviderIf> schema) {
     SchemaVer ver = getSchemaVer(row);
     CHECK_EQ(ver, schema->getVersion());
-    return std::unique_ptr<RowReader>(new RowReader(row, std::move(schema)));
+    return RowReader(row, std::move(schema));
 }
 
-
 // static
 int32_t RowReader::getSchemaVer(folly::StringPiece row) {
     const uint8_t* it = reinterpret_cast<const uint8_t*>(row.begin());
diff --git a/src/dataman/RowReader.h b/src/dataman/RowReader.h
index b2bfb876e34..4f796a6fc82 100644
--- a/src/dataman/RowReader.h
+++ b/src/dataman/RowReader.h
@@ -72,22 +72,31 @@ class RowReader {
 
 
 public:
-    static std::unique_ptr<RowReader> getTagPropReader(
+    RowReader(const RowReader&) = delete;
+    RowReader& operator=(const RowReader&) = delete;
+    RowReader(RowReader&& x) = default;
+    RowReader& operator=(RowReader&& x) = default;
+
+    static RowReader getTagPropReader(
         meta::SchemaManager* schemaMan,
         folly::StringPiece row,
         GraphSpaceID space,
         TagID tag);
 
-    static std::unique_ptr<RowReader> getEdgePropReader(
+    static RowReader getEdgePropReader(
         meta::SchemaManager* schemaMan,
         folly::StringPiece row,
         GraphSpaceID space,
         EdgeType edge);
 
-    static std::unique_ptr<RowReader> getRowReader(
+    static RowReader getRowReader(
         folly::StringPiece row,
         std::shared_ptr<const meta::SchemaProviderIf> schema);
 
+    static RowReader getEmptyRowReader() {
+        return RowReader();
+    }
+
     static StatusOr<VariantType> getDefaultProp(const meta::SchemaProviderIf* schema,
                                                 const std::string& prop) {
         auto& vType = schema->getFieldType(prop);
@@ -242,9 +251,6 @@ class RowReader {
                 return ResultType::E_DATA_INVALID;
         }
     }
-
-    virtual ~RowReader() = default;
-
     SchemaVer schemaVer() const noexcept;
     int32_t numFields() const noexcept;
 
@@ -286,6 +292,47 @@ class RowReader {
         return data_;
     }
 
+    operator bool() const noexcept {
+        return operator!=(nullptr);
+    }
+
+    bool operator==(std::nullptr_t) const noexcept {
+        return !data_.data();
+    }
+
+    bool operator==(const RowReader& x) const noexcept {
+        return data_ == x.data_;
+    }
+
+    bool operator!=(std::nullptr_t) const noexcept {
+        return static_cast<bool>(data_.data());
+    }
+
+    bool operator!=(const RowReader& x) const noexcept {
+        return data_ != x.data_;
+    }
+
+    RowReader* operator->() const noexcept {
+        return get();
+    }
+
+    RowReader* get() const noexcept {
+        return const_cast<RowReader*>(this);
+    }
+
+    RowReader* get() noexcept {
+        return this;
+    }
+
+    RowReader& operator*() const noexcept {
+        return *get();
+    }
+
+    void reset() noexcept {
+        this->~RowReader();
+        new(this) RowReader();
+    }
+
     // TODO getPath(const std::string& name) const noexcept;
     // TODO getPath(int64_t index) const noexcept;
     // TODO getList(const std::string& name) const noexcept;
@@ -308,6 +355,7 @@ class RowReader {
     mutable std::vector<int64_t> offsets_;
 
 private:
+    RowReader() = default;
     RowReader(folly::StringPiece row,
               std::shared_ptr<const meta::SchemaProviderIf> schema);
 
diff --git a/src/dataman/RowSetReader.h b/src/dataman/RowSetReader.h
index c84aaaa65bd..3a30a0fb460 100644
--- a/src/dataman/RowSetReader.h
+++ b/src/dataman/RowSetReader.h
@@ -7,6 +7,7 @@
 #ifndef DATAMAN_ROWSETREADER_H_
 #define DATAMAN_ROWSETREADER_H_
 
+#include "RowReader.h"
 #include "base/Base.h"
 #include "gen-cpp2/storage_types.h"
 #include "meta/SchemaProviderIf.h"
@@ -33,7 +34,7 @@ class RowSetReader {
         // The total length of the encoded row set
         const folly::StringPiece& data_;
 
-        std::unique_ptr<RowReader> reader_;
+        RowReader reader_ = RowReader::getEmptyRowReader();
         // The offset of the current row
         int64_t offset_;
         // The length of the current row
diff --git a/src/dataman/RowUpdater.cpp b/src/dataman/RowUpdater.cpp
index 853a6865233..5546b10123c 100644
--- a/src/dataman/RowUpdater.cpp
+++ b/src/dataman/RowUpdater.cpp
@@ -12,7 +12,7 @@ namespace nebula {
 using folly::hash::SpookyHashV2;
 using nebula::meta::SchemaProviderIf;
 
-RowUpdater::RowUpdater(std::unique_ptr<RowReader> reader,
+RowUpdater::RowUpdater(RowReader reader,
                        std::shared_ptr<const meta::SchemaProviderIf> schema)
         : schema_(std::move(schema))
         , reader_(std::move(reader)) {
@@ -22,7 +22,7 @@ RowUpdater::RowUpdater(std::unique_ptr<RowReader> reader,
 
 RowUpdater::RowUpdater(std::shared_ptr<const meta::SchemaProviderIf> schema)
         : schema_(std::move(schema))
-        , reader_(nullptr) {
+        , reader_(RowReader::getEmptyRowReader()) {
     CHECK(!!schema_);
 }
 
diff --git a/src/dataman/RowUpdater.h b/src/dataman/RowUpdater.h
index ab1b3887bb2..708785023eb 100644
--- a/src/dataman/RowUpdater.h
+++ b/src/dataman/RowUpdater.h
@@ -27,7 +27,7 @@ class RowUpdater {
     // reader holds the original data
     // schema is the writer schema, which means the updated data will be encoded
     //   using this schema
-    RowUpdater(std::unique_ptr<RowReader> reader,
+    RowUpdater(RowReader reader,
                std::shared_ptr<const meta::SchemaProviderIf> schema);
     explicit RowUpdater(std::shared_ptr<const meta::SchemaProviderIf> schema);
 
@@ -79,7 +79,7 @@ class RowUpdater {
 
 private:
     std::shared_ptr<const meta::SchemaProviderIf> schema_;
-    std::unique_ptr<RowReader> reader_;
+    RowReader reader_ = RowReader::getEmptyRowReader();
     // Hash64(field_name) => value
     std::unordered_map<uint64_t, FieldValue> updatedFields_;
 };
diff --git a/src/graph/FetchVerticesExecutor.cpp b/src/graph/FetchVerticesExecutor.cpp
index ddd0f043777..b6ef4b54117 100644
--- a/src/graph/FetchVerticesExecutor.cpp
+++ b/src/graph/FetchVerticesExecutor.cpp
@@ -364,7 +364,7 @@ void FetchVerticesExecutor::processResult(RpcResponse &&result) {
         finishExecution(std::move(rsWriter));
         return;
     }
-    std::unordered_map<VertexID, std::map<TagID, std::unique_ptr<RowReader>>> dataMap;
+    std::unordered_map<VertexID, std::map<TagID, RowReader>> dataMap;
     dataMap.reserve(num);
 
     std::unordered_map<TagID, std::shared_ptr<const meta::SchemaProviderIf>> tagSchemaMap;
@@ -407,7 +407,7 @@ void FetchVerticesExecutor::processResult(RpcResponse &&result) {
                 }
                 auto vschema = tagSchemaMap[tagId];
                 auto vreader = RowReader::getRowReader(data, vschema);
-                dataMap[vid][tagId] = std::move(vreader);
+                dataMap[vid].emplace(std::make_pair(tagId, std::move(vreader)));
                 tagIdSet.insert(tagId);
             }
         }
diff --git a/src/graph/GoExecutor.cpp b/src/graph/GoExecutor.cpp
index d73c191e887..cf8a61b0555 100644
--- a/src/graph/GoExecutor.cpp
+++ b/src/graph/GoExecutor.cpp
@@ -926,7 +926,7 @@ void GoExecutor::fetchVertexProps(std::vector<VertexID> ids) {
     auto returns = status.value();
     auto future = ectx()->getStorageClient()->getVertexProps(spaceId, ids, returns);
     auto *runner = ectx()->rctx()->runner();
-    auto cb = [this] (auto &&result) mutable {
+    auto cb = [this, ectx = ectx()] (auto &&result) mutable {
         auto completeness = result.completeness();
         if (completeness == 0) {
             doError(Status::Error("Get dest props failed"));
@@ -939,7 +939,7 @@ void GoExecutor::fetchVertexProps(std::vector<VertexID> ids) {
             }
         }
         if (vertexHolder_ == nullptr) {
-            vertexHolder_ = std::make_unique<VertexHolder>();
+            vertexHolder_ = std::make_unique<VertexHolder>(ectx);
         }
         for (auto &resp : result.responses()) {
             vertexHolder_->add(resp);
@@ -1222,7 +1222,7 @@ bool GoExecutor::processFinalResult(Callback cb) const {
                                 return index_->getColumnWithRow(*inputRow, prop);
                             };
 
-                            std::unique_ptr<RowReader> reader;
+                            RowReader reader = RowReader::getEmptyRowReader();
                             if (currEdgeSchema) {
                                 reader = RowReader::getRowReader(edge.props, currEdgeSchema);
                             }
@@ -1315,28 +1315,24 @@ bool GoExecutor::processFinalResult(Callback cb) const {
     return true;
 }
 
-OptVariantType GoExecutor::VertexHolder::getDefaultProp(TagID tid, const std::string &prop) const {
-    for (auto it = data_.cbegin(); it != data_.cend(); ++it) {
-        auto it2 = it->second.find(tid);
-        if (it2 != it->second.cend()) {
-            return RowReader::getDefaultProp(std::get<0>(it2->second).get(), prop);
-        }
+OptVariantType GoExecutor::VertexHolder::getDefaultProp(
+    TagID tagId, const std::string &prop) const {
+    auto space = ectx_->rctx()->session()->space();
+    auto schema = ectx_->schemaManager()->getTagSchema(space, tagId);
+    if (schema == nullptr) {
+        return Status::Error("No tag schema for tagId %d", tagId);
     }
-
-
-    return Status::Error("Unknown property: `%s'", prop.c_str());
+    return RowReader::getDefaultProp(schema.get(), prop);
 }
 
-SupportedType GoExecutor::VertexHolder::getDefaultPropType(TagID tid,
-                                                           const std::string &prop) const {
-    for (auto it = data_.cbegin(); it != data_.cend(); ++it) {
-        auto it2 = it->second.find(tid);
-        if (it2 != it->second.cend()) {
-            return std::get<0>(it2->second)->getFieldType(prop).type;
-        }
+SupportedType GoExecutor::VertexHolder::getDefaultPropType(
+    TagID tagId, const std::string &prop) const {
+    auto space = ectx_->rctx()->session()->space();
+    auto schema = ectx_->schemaManager()->getTagSchema(space, tagId);
+    if (schema == nullptr) {
+        return nebula::cpp2::SupportedType::UNKNOWN;
     }
-
-    return nebula::cpp2::SupportedType::UNKNOWN;
+    return schema->getFieldType(prop).type;
 }
 
 OptVariantType GoExecutor::VertexHolder::get(VertexID id, TagID tid,
diff --git a/src/graph/GoExecutor.h b/src/graph/GoExecutor.h
index 283c9423aa6..0fd66973e0c 100644
--- a/src/graph/GoExecutor.h
+++ b/src/graph/GoExecutor.h
@@ -175,6 +175,7 @@ class GoExecutor final : public TraverseExecutor {
      */
     class VertexHolder final {
     public:
+        explicit VertexHolder(ExecutionContext* ectx) : ectx_(ectx) { }
         OptVariantType getDefaultProp(TagID tid, const std::string &prop) const;
         OptVariantType get(VertexID id, TagID tid, const std::string &prop) const;
         void add(const storage::cpp2::QueryResponse &resp);
@@ -184,6 +185,7 @@ class GoExecutor final : public TraverseExecutor {
     private:
         using VData = std::tuple<std::shared_ptr<ResultSchemaProvider>, std::string>;
         std::unordered_map<VertexID, std::unordered_map<TagID, VData>> data_;
+        ExecutionContext* ectx_{nullptr};
     };
 
     class VertexBackTracker final {
diff --git a/src/storage/mutate/AddEdgesProcessor.cpp b/src/storage/mutate/AddEdgesProcessor.cpp
index e16f2bedea9..83ef882d6e8 100644
--- a/src/storage/mutate/AddEdgesProcessor.cpp
+++ b/src/storage/mutate/AddEdgesProcessor.cpp
@@ -87,7 +87,7 @@ std::string AddEdgesProcessor::addEdges(int64_t version, PartitionID partId,
     });
     for (auto& e : newEdges) {
         std::string val;
-        std::unique_ptr<RowReader> nReader;
+        RowReader nReader = RowReader::getEmptyRowReader();
         auto edgeType = NebulaKeyUtils::getEdgeType(e.first);
         for (auto& index : indexes_) {
             if (edgeType == index->get_schema_id().get_edge_type()) {
diff --git a/src/storage/mutate/AddVerticesProcessor.cpp b/src/storage/mutate/AddVerticesProcessor.cpp
index 814bb4318b5..10e0083b85a 100644
--- a/src/storage/mutate/AddVerticesProcessor.cpp
+++ b/src/storage/mutate/AddVerticesProcessor.cpp
@@ -103,7 +103,7 @@ std::string AddVerticesProcessor::addVertices(int64_t version, PartitionID partI
 
     for (auto& v : newVertices) {
         std::string val;
-        std::unique_ptr<RowReader> nReader;
+        RowReader nReader = RowReader::getEmptyRowReader();
         auto tagId = NebulaKeyUtils::getTagId(v.first);
         auto vId = NebulaKeyUtils::getVertexId(v.first);
         for (auto& index : indexes_) {
diff --git a/src/storage/mutate/DeleteEdgesProcessor.cpp b/src/storage/mutate/DeleteEdgesProcessor.cpp
index d74dca77ffe..589bc7babda 100644
--- a/src/storage/mutate/DeleteEdgesProcessor.cpp
+++ b/src/storage/mutate/DeleteEdgesProcessor.cpp
@@ -98,7 +98,7 @@ DeleteEdgesProcessor::deleteEdges(GraphSpaceID spaceId,
              * just get the latest version edge for index.
              */
             if (isLatestVE) {
-                std::unique_ptr<RowReader> reader;
+                RowReader reader = RowReader::getEmptyRowReader();
                 for (auto& index : indexes_) {
                     auto indexId = index->get_index_id();
                     if (type == index->get_schema_id().get_edge_type()) {
diff --git a/src/storage/mutate/DeleteVerticesProcessor.cpp b/src/storage/mutate/DeleteVerticesProcessor.cpp
index d90574e5272..2e84ff9d760 100644
--- a/src/storage/mutate/DeleteVerticesProcessor.cpp
+++ b/src/storage/mutate/DeleteVerticesProcessor.cpp
@@ -119,7 +119,7 @@ DeleteVerticesProcessor::deleteVertices(GraphSpaceID spaceId,
              * Using newlyVertexId to identify if it is the latest version
              */
             if (latestVVId != tagId) {
-                std::unique_ptr<RowReader> reader;
+                RowReader reader = RowReader::getEmptyRowReader();
                 for (auto& index : indexes_) {
                     auto indexId = index->get_index_id();
                     if (index->get_schema_id().get_tag_id() == tagId) {
diff --git a/src/storage/mutate/UpdateEdgeProcessor.cpp b/src/storage/mutate/UpdateEdgeProcessor.cpp
index feef1c4e504..38adf96c4a7 100644
--- a/src/storage/mutate/UpdateEdgeProcessor.cpp
+++ b/src/storage/mutate/UpdateEdgeProcessor.cpp
@@ -403,7 +403,8 @@ folly::Optional<std::string> UpdateEdgeProcessor::updateAndWriteBack(PartitionID
     auto nVal = std::move(status.value());
     // TODO(heng) we don't update the index for reverse edge.
     if (!indexes_.empty() && edgeKey.edge_type > 0) {
-        std::unique_ptr<RowReader> reader, rReader;
+        RowReader reader = RowReader::getEmptyRowReader();
+        RowReader rReader = RowReader::getEmptyRowReader();
         for (auto& index : indexes_) {
             auto indexId = index->get_index_id();
             if (index->get_schema_id().get_edge_type() == edgeKey.edge_type) {
diff --git a/src/storage/mutate/UpdateVertexProcessor.cpp b/src/storage/mutate/UpdateVertexProcessor.cpp
index 4a8df8fb03d..3a22af5b426 100644
--- a/src/storage/mutate/UpdateVertexProcessor.cpp
+++ b/src/storage/mutate/UpdateVertexProcessor.cpp
@@ -410,7 +410,8 @@ folly::Optional<std::string> UpdateVertexProcessor::updateAndWriteBack(const Par
         }
         auto nVal = std::move(status.value());
         if (!indexes_.empty()) {
-            std::unique_ptr<RowReader> reader, oReader;
+            RowReader reader = RowReader::getEmptyRowReader();
+            RowReader oReader = RowReader::getEmptyRowReader();
             for (auto &index : indexes_) {
                 if (index->get_schema_id().get_tag_id() == u.first) {
                     if (!(u.second->kv.second.empty())) {
diff --git a/src/storage/query/QueryBaseProcessor.h b/src/storage/query/QueryBaseProcessor.h
index 4409a04d80e..98c615e31df 100644
--- a/src/storage/query/QueryBaseProcessor.h
+++ b/src/storage/query/QueryBaseProcessor.h
@@ -26,9 +26,7 @@ const std::unordered_map<std::string, PropContext::PropInKeyType> kPropsInKey_ =
     {"_rank", PropContext::PropInKeyType::RANK}
 };
 
-using EdgeProcessor
-    = std::function<void(std::unique_ptr<RowReader> reader,
-                         folly::StringPiece key)>;
+using EdgeProcessor = std::function<void(RowReader reader, folly::StringPiece key)>;
 struct Bucket {
     std::vector<std::pair<PartitionID, VertexID>> vertices_;
 };
diff --git a/src/storage/query/QueryBaseProcessor.inl b/src/storage/query/QueryBaseProcessor.inl
index 9c256cfbd77..b0a6ee447bc 100644
--- a/src/storage/query/QueryBaseProcessor.inl
+++ b/src/storage/query/QueryBaseProcessor.inl
@@ -516,7 +516,7 @@ kvstore::ResultCode QueryBaseProcessor<REQ, RESP>::collectEdgeProps(
         }
         lastRank = rank;
         lastDstId = dstId;
-        std::unique_ptr<RowReader> reader;
+        RowReader reader = RowReader::getEmptyRowReader();
         if ((!onlyStructure || retTTL.has_value()) && !val.empty()) {
             reader = RowReader::getEdgePropReader(this->schemaMan_,
                                                   val,
diff --git a/src/storage/query/QueryBoundProcessor.cpp b/src/storage/query/QueryBoundProcessor.cpp
index cabc6219da6..5ada25b46ea 100644
--- a/src/storage/query/QueryBoundProcessor.cpp
+++ b/src/storage/query/QueryBoundProcessor.cpp
@@ -35,8 +35,7 @@ kvstore::ResultCode QueryBoundProcessor::processEdgeImpl(const PartitionID partI
     edges.reserve(FLAGS_reserved_edges_one_vertex);
     auto ret = collectEdgeProps(
         partId, vId, edgeType, &fcontext,
-        [&, this](std::unique_ptr<RowReader> reader,
-                  folly::StringPiece k) {
+        [&, this](RowReader reader, folly::StringPiece k) {
             cpp2::IdAndProp edge;
             if (!onlyStructure) {
                 RowWriter writer(currEdgeSchema);
@@ -112,11 +111,12 @@ kvstore::ResultCode QueryBoundProcessor::processEdgeSampling(const PartitionID p
             CHECK(!onlyVertexProps_);
             auto ret = collectEdgeProps(
                 partId, vId, edgeType, &fcontext,
-                [&](std::unique_ptr<RowReader> reader,
-                    folly::StringPiece k) {
+                [&](RowReader reader, folly::StringPiece k) {
                     sampler->sampling(
-                        std::make_tuple(edgeType, k.str(), std::move(reader),
-                                        currEdgeSchema, props));
+                        std::make_tuple(
+                            edgeType, k.str(),
+                            std::make_unique<RowReader>(std::move(reader)),
+                            currEdgeSchema, props));
                 });
             if (ret != kvstore::ResultCode::SUCCEEDED) {
                 return ret;
diff --git a/src/storage/query/QueryStatsProcessor.cpp b/src/storage/query/QueryStatsProcessor.cpp
index 2a7c4fc9c85..d127bc572ed 100644
--- a/src/storage/query/QueryStatsProcessor.cpp
+++ b/src/storage/query/QueryStatsProcessor.cpp
@@ -86,7 +86,7 @@ kvstore::ResultCode QueryStatsProcessor::processVertex(PartitionID partId,
         auto& props = ec.second;
         if (!props.empty()) {
             auto r = this->collectEdgeProps(partId, vId, edgeType, &fcontext,
-                                            [&, this](std::unique_ptr<RowReader> reader,
+                                            [&, this](RowReader reader,
                                                       folly::StringPiece key) {
                                                 this->collectProps(
                                                         reader.get(), key, props, &fcontext,