diff --git a/core/include/collection_c.h b/core/include/collection_c.h
index 5d3c8aea2f..b2b5b39070 100644
--- a/core/include/collection_c.h
+++ b/core/include/collection_c.h
@@ -10,6 +10,9 @@ NewCollection(const char* collection_name, const char* schema_conf);
 void
 DeleteCollection(CCollection collection);
 
+void
+UpdateIndexes(CCollection c_collection, const char *index_string);
+
 #ifdef __cplusplus
 }
 #endif
\ No newline at end of file
diff --git a/core/include/segment_c.h b/core/include/segment_c.h
index 116f6de2e2..4713daa78f 100644
--- a/core/include/segment_c.h
+++ b/core/include/segment_c.h
@@ -68,7 +68,7 @@ int
 Close(CSegmentBase c_segment);
 
 int
-BuildIndex(CSegmentBase c_segment);
+BuildIndex(CCollection c_collection, CSegmentBase c_segment);
 
 bool
 IsOpened(CSegmentBase c_segment);
diff --git a/core/src/dog_segment/Collection.cpp b/core/src/dog_segment/Collection.cpp
index e16e4a08a8..491a110db3 100644
--- a/core/src/dog_segment/Collection.cpp
+++ b/core/src/dog_segment/Collection.cpp
@@ -10,6 +10,7 @@ namespace milvus::dog_segment {
 Collection::Collection(std::string &collection_name, std::string &schema):
       collection_name_(collection_name), schema_json_(schema) {
     parse();
+    index_ = nullptr;
 }
 
 
@@ -91,6 +92,7 @@ Collection::AddIndex(const grpc::IndexParam& index_param) {
 
 void
 Collection::CreateIndex(std::string &index_config) {
+
     if(index_config.empty()) {
         index_ = nullptr;
         std::cout << "null index config when create index" << std::endl;
@@ -118,6 +120,7 @@ Collection::CreateIndex(std::string &index_config) {
 void
 Collection::parse() {
     if(schema_json_.empty()) {
+        std::cout << "WARN: Use default schema" << std::endl;
         auto schema = std::make_shared<Schema>();
         schema->AddField("fakevec", DataType::VECTOR_FLOAT, 16);
         schema->AddField("age", DataType::INT32);
diff --git a/core/src/dog_segment/SegmentNaive.cpp b/core/src/dog_segment/SegmentNaive.cpp
index 401335dd8e..0500793f0f 100644
--- a/core/src/dog_segment/SegmentNaive.cpp
+++ b/core/src/dog_segment/SegmentNaive.cpp
@@ -551,6 +551,8 @@ knowhere::IndexPtr SegmentNaive::BuildVecIndexImpl(const IndexMeta::Entry &entry
 Status
 SegmentNaive::BuildIndex(IndexMetaPtr remote_index_meta) {
     if (remote_index_meta == nullptr) {
+        std::cout << "WARN: Null index ptr is detected, use default index" << std::endl;
+
         int dim = 0;
         std::string index_field_name;
 
diff --git a/core/src/dog_segment/collection_c.cpp b/core/src/dog_segment/collection_c.cpp
index 15d8d96ec1..719052d5de 100644
--- a/core/src/dog_segment/collection_c.cpp
+++ b/core/src/dog_segment/collection_c.cpp
@@ -22,7 +22,8 @@ DeleteCollection(CCollection collection) {
   delete col;
 }
 
-void UpdateIndexes(CCollection c_collection, const char *index_string) {
+void
+UpdateIndexes(CCollection c_collection, const char *index_string) {
   auto c = (milvus::dog_segment::Collection*)c_collection;
   std::string s(index_string);
   c->CreateIndex(s);
diff --git a/core/src/dog_segment/collection_c.h b/core/src/dog_segment/collection_c.h
index e505b7f38d..b2b5b39070 100644
--- a/core/src/dog_segment/collection_c.h
+++ b/core/src/dog_segment/collection_c.h
@@ -10,7 +10,8 @@ NewCollection(const char* collection_name, const char* schema_conf);
 void
 DeleteCollection(CCollection collection);
 
-void UpdateIndexes(CCollection c_collection, const char *index_string);
+void
+UpdateIndexes(CCollection c_collection, const char *index_string);
 
 #ifdef __cplusplus
 }
diff --git a/core/src/dog_segment/segment_c.cpp b/core/src/dog_segment/segment_c.cpp
index 9657179100..9cbc028a45 100644
--- a/core/src/dog_segment/segment_c.cpp
+++ b/core/src/dog_segment/segment_c.cpp
@@ -166,6 +166,7 @@ int
 BuildIndex(CCollection c_collection, CSegmentBase c_segment) {
     auto collection = (milvus::dog_segment::Collection*)c_collection;
     auto segment = (milvus::dog_segment::SegmentBase*)c_segment;
+
     auto status = segment->BuildIndex(collection->get_index());
     return status.code();
 }
diff --git a/core/src/index/cmake/ThirdPartyPackagesCore.cmake b/core/src/index/cmake/ThirdPartyPackagesCore.cmake
index f8e769147f..ea45bfd885 100644
--- a/core/src/index/cmake/ThirdPartyPackagesCore.cmake
+++ b/core/src/index/cmake/ThirdPartyPackagesCore.cmake
@@ -32,7 +32,8 @@ macro(build_dependency DEPENDENCY_NAME)
     if ("${DEPENDENCY_NAME}" STREQUAL "Arrow")
         build_arrow()
     elseif ("${DEPENDENCY_NAME}" STREQUAL "GTest")
-        build_gtest()
+#        build_gtest()
+#        find_package(GTest REQUIRED)
     elseif ("${DEPENDENCY_NAME}" STREQUAL "OpenBLAS")
         build_openblas()
     elseif ("${DEPENDENCY_NAME}" STREQUAL "FAISS")
@@ -386,88 +387,88 @@ endif()
 # ----------------------------------------------------------------------
 # Google gtest
 
-macro(build_gtest)
-    message(STATUS "Building gtest-${GTEST_VERSION} from source")
-    set(GTEST_VENDORED TRUE)
-    set(GTEST_CMAKE_CXX_FLAGS "${EP_CXX_FLAGS}")
-
-    if (APPLE)
-        set(GTEST_CMAKE_CXX_FLAGS
-                ${GTEST_CMAKE_CXX_FLAGS}
-                -DGTEST_USE_OWN_TR1_TUPLE=1
-                -Wno-unused-value
-                -Wno-ignored-attributes)
-    endif ()
-
-    set(GTEST_PREFIX "${INDEX_BINARY_DIR}/googletest_ep-prefix/src/googletest_ep")
-    set(GTEST_INCLUDE_DIR "${GTEST_PREFIX}/include")
-    set(GTEST_STATIC_LIB
-            "${GTEST_PREFIX}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}gtest${CMAKE_STATIC_LIBRARY_SUFFIX}")
-    set(GTEST_MAIN_STATIC_LIB
-            "${GTEST_PREFIX}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}gtest_main${CMAKE_STATIC_LIBRARY_SUFFIX}")
-
-    set(GTEST_CMAKE_ARGS
-            ${EP_COMMON_CMAKE_ARGS}
-            "-DCMAKE_INSTALL_PREFIX=${GTEST_PREFIX}"
-            "-DCMAKE_INSTALL_LIBDIR=lib"
-            -DCMAKE_CXX_FLAGS=${GTEST_CMAKE_CXX_FLAGS}
-            -DCMAKE_BUILD_TYPE=Release)
-
-    set(GMOCK_INCLUDE_DIR "${GTEST_PREFIX}/include")
-    set(GMOCK_STATIC_LIB
-            "${GTEST_PREFIX}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}gmock${CMAKE_STATIC_LIBRARY_SUFFIX}"
-            )
-
-        ExternalProject_Add(googletest_ep
-                URL
-                ${GTEST_SOURCE_URL}
-                BUILD_COMMAND
-                ${MAKE}
-                ${MAKE_BUILD_ARGS}
-                BUILD_BYPRODUCTS
-                ${GTEST_STATIC_LIB}
-                ${GTEST_MAIN_STATIC_LIB}
-                ${GMOCK_STATIC_LIB}
-                CMAKE_ARGS
-                ${GTEST_CMAKE_ARGS}
-                ${EP_LOG_OPTIONS})
-
-    # The include directory must exist before it is referenced by a target.
-    file(MAKE_DIRECTORY "${GTEST_INCLUDE_DIR}")
-
-    add_library(gtest STATIC IMPORTED)
-    set_target_properties(gtest
-            PROPERTIES IMPORTED_LOCATION "${GTEST_STATIC_LIB}"
-            INTERFACE_INCLUDE_DIRECTORIES "${GTEST_INCLUDE_DIR}")
-
-    add_library(gtest_main STATIC IMPORTED)
-    set_target_properties(gtest_main
-            PROPERTIES IMPORTED_LOCATION "${GTEST_MAIN_STATIC_LIB}"
-            INTERFACE_INCLUDE_DIRECTORIES "${GTEST_INCLUDE_DIR}")
-
-    add_library(gmock STATIC IMPORTED)
-    set_target_properties(gmock
-            PROPERTIES IMPORTED_LOCATION "${GMOCK_STATIC_LIB}"
-            INTERFACE_INCLUDE_DIRECTORIES "${GTEST_INCLUDE_DIR}")
-
-    add_dependencies(gtest googletest_ep)
-    add_dependencies(gtest_main googletest_ep)
-    add_dependencies(gmock googletest_ep)
-
-endmacro()
+#macro(build_gtest)
+#    message(STATUS "Building gtest-${GTEST_VERSION} from source")
+#    set(GTEST_VENDORED TRUE)
+#    set(GTEST_CMAKE_CXX_FLAGS "${EP_CXX_FLAGS}")
+#
+#    if (APPLE)
+#        set(GTEST_CMAKE_CXX_FLAGS
+#                ${GTEST_CMAKE_CXX_FLAGS}
+#                -DGTEST_USE_OWN_TR1_TUPLE=1
+#                -Wno-unused-value
+#                -Wno-ignored-attributes)
+#    endif ()
+#
+#    set(GTEST_PREFIX "${INDEX_BINARY_DIR}/googletest_ep-prefix/src/googletest_ep")
+#    set(GTEST_INCLUDE_DIR "${GTEST_PREFIX}/include")
+#    set(GTEST_STATIC_LIB
+#            "${GTEST_PREFIX}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}gtest${CMAKE_STATIC_LIBRARY_SUFFIX}")
+#    set(GTEST_MAIN_STATIC_LIB
+#            "${GTEST_PREFIX}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}gtest_main${CMAKE_STATIC_LIBRARY_SUFFIX}")
+#
+#    set(GTEST_CMAKE_ARGS
+#            ${EP_COMMON_CMAKE_ARGS}
+#            "-DCMAKE_INSTALL_PREFIX=${GTEST_PREFIX}"
+#            "-DCMAKE_INSTALL_LIBDIR=lib"
+#            -DCMAKE_CXX_FLAGS=${GTEST_CMAKE_CXX_FLAGS}
+#            -DCMAKE_BUILD_TYPE=Release)
+#
+#    set(GMOCK_INCLUDE_DIR "${GTEST_PREFIX}/include")
+#    set(GMOCK_STATIC_LIB
+#            "${GTEST_PREFIX}/lib/${CMAKE_STATIC_LIBRARY_PREFIX}gmock${CMAKE_STATIC_LIBRARY_SUFFIX}"
+#            )
+#
+#        ExternalProject_Add(googletest_ep
+#                URL
+#                ${GTEST_SOURCE_URL}
+#                BUILD_COMMAND
+#                ${MAKE}
+#                ${MAKE_BUILD_ARGS}
+#                BUILD_BYPRODUCTS
+#                ${GTEST_STATIC_LIB}
+#                ${GTEST_MAIN_STATIC_LIB}
+#                ${GMOCK_STATIC_LIB}
+#                CMAKE_ARGS
+#                ${GTEST_CMAKE_ARGS}
+#                ${EP_LOG_OPTIONS})
+#
+#    # The include directory must exist before it is referenced by a target.
+#    file(MAKE_DIRECTORY "${GTEST_INCLUDE_DIR}")
+#
+#    add_library(gtest STATIC IMPORTED)
+#    set_target_properties(gtest
+#            PROPERTIES IMPORTED_LOCATION "${GTEST_STATIC_LIB}"
+#            INTERFACE_INCLUDE_DIRECTORIES "${GTEST_INCLUDE_DIR}")
+#
+#    add_library(gtest_main STATIC IMPORTED)
+#    set_target_properties(gtest_main
+#            PROPERTIES IMPORTED_LOCATION "${GTEST_MAIN_STATIC_LIB}"
+#            INTERFACE_INCLUDE_DIRECTORIES "${GTEST_INCLUDE_DIR}")
+#
+#    add_library(gmock STATIC IMPORTED)
+#    set_target_properties(gmock
+#            PROPERTIES IMPORTED_LOCATION "${GMOCK_STATIC_LIB}"
+#            INTERFACE_INCLUDE_DIRECTORIES "${GTEST_INCLUDE_DIR}")
+#
+#    add_dependencies(gtest googletest_ep)
+#    add_dependencies(gtest_main googletest_ep)
+#    add_dependencies(gmock googletest_ep)
+#
+#endmacro()
 
 # if (KNOWHERE_BUILD_TESTS AND NOT TARGET googletest_ep)
-if ( NOT TARGET gtest AND KNOWHERE_BUILD_TESTS )
-    resolve_dependency(GTest)
-
-    if (NOT GTEST_VENDORED)
-    endif ()
-
-    # TODO: Don't use global includes but rather target_include_directories
-    get_target_property(GTEST_INCLUDE_DIR gtest INTERFACE_INCLUDE_DIRECTORIES)
-    link_directories(SYSTEM "${GTEST_PREFIX}/lib")
-    include_directories(SYSTEM ${GTEST_INCLUDE_DIR})
-endif ()
+#if ( NOT TARGET gtest AND KNOWHERE_BUILD_TESTS )
+#    resolve_dependency(GTest)
+#
+#    if (NOT GTEST_VENDORED)
+#    endif ()
+#
+#    # TODO: Don't use global includes but rather target_include_directories
+#    get_target_property(GTEST_INCLUDE_DIR gtest INTERFACE_INCLUDE_DIRECTORIES)
+#    link_directories(SYSTEM "${GTEST_PREFIX}/lib")
+#    include_directories(SYSTEM ${GTEST_INCLUDE_DIR})
+#endif ()
 
 # ----------------------------------------------------------------------
 # MKL
diff --git a/core/unittest/test_c_api.cpp b/core/unittest/test_c_api.cpp
index 3ec8d98b68..dcb2beb4e7 100644
--- a/core/unittest/test_c_api.cpp
+++ b/core/unittest/test_c_api.cpp
@@ -11,7 +11,7 @@ namespace chrono = std::chrono;
 
 TEST(CApiTest, CollectionTest) {
     auto collection_name = "collection0";
-    auto schema_tmp_conf = "null_schema";
+    auto schema_tmp_conf = "";
     auto collection = NewCollection(collection_name, schema_tmp_conf);
     DeleteCollection(collection);
 }
@@ -19,7 +19,7 @@ TEST(CApiTest, CollectionTest) {
 
 TEST(CApiTest, PartitonTest) {
     auto collection_name = "collection0";
-    auto schema_tmp_conf = "null_schema";
+    auto schema_tmp_conf = "";
     auto collection = NewCollection(collection_name, schema_tmp_conf);
     auto partition_name = "partition0";
     auto partition = NewPartition(collection, partition_name);
@@ -30,7 +30,7 @@ TEST(CApiTest, PartitonTest) {
 
 TEST(CApiTest, SegmentTest) {
     auto collection_name = "collection0";
-    auto schema_tmp_conf = "null_schema";
+    auto schema_tmp_conf = "";
     auto collection = NewCollection(collection_name, schema_tmp_conf);
     auto partition_name = "partition0";
     auto partition = NewPartition(collection, partition_name);
@@ -43,7 +43,7 @@ TEST(CApiTest, SegmentTest) {
 
 TEST(CApiTest, InsertTest) {
     auto collection_name = "collection0";
-    auto schema_tmp_conf = "null_schema";
+    auto schema_tmp_conf = "";
     auto collection = NewCollection(collection_name, schema_tmp_conf);
     auto partition_name = "partition0";
     auto partition = NewPartition(collection, partition_name);
@@ -92,7 +92,7 @@ TEST(CApiTest, InsertTest) {
 
 TEST(CApiTest, DeleteTest) {
     auto collection_name = "collection0";
-    auto schema_tmp_conf = "null_schema";
+    auto schema_tmp_conf = "";
     auto collection = NewCollection(collection_name, schema_tmp_conf);
     auto partition_name = "partition0";
     auto partition = NewPartition(collection, partition_name);
@@ -114,7 +114,7 @@ TEST(CApiTest, DeleteTest) {
 
 TEST(CApiTest, SearchTest) {
     auto collection_name = "collection0";
-    auto schema_tmp_conf = "null_schema";
+    auto schema_tmp_conf = "";
     auto collection = NewCollection(collection_name, schema_tmp_conf);
     auto partition_name = "partition0";
     auto partition = NewPartition(collection, partition_name);
@@ -176,9 +176,9 @@ TEST(CApiTest, SearchTest) {
 }
 
 
-TEST(CApiTest, SearchSimpleTest) {
+TEST(CApiTest, BuildIndexTest) {
     auto collection_name = "collection0";
-    auto schema_tmp_conf = "null_schema";
+    auto schema_tmp_conf = "";
     auto collection = NewCollection(collection_name, schema_tmp_conf);
     auto partition_name = "partition0";
     auto partition = NewPartition(collection, partition_name);
@@ -223,8 +223,9 @@ TEST(CApiTest, SearchSimpleTest) {
                           N);
     assert(ins_res == 0);
 
+    // TODO: add index ptr
     Close(segment);
-    BuildIndex(segment);
+    BuildIndex(collection, segment);
 
     long result_ids[10];
     float result_distances[10];
@@ -248,7 +249,7 @@ TEST(CApiTest, SearchSimpleTest) {
 
 TEST(CApiTest, IsOpenedTest) {
     auto collection_name = "collection0";
-    auto schema_tmp_conf = "null_schema";
+    auto schema_tmp_conf = "";
     auto collection = NewCollection(collection_name, schema_tmp_conf);
     auto partition_name = "partition0";
     auto partition = NewPartition(collection, partition_name);
@@ -265,7 +266,7 @@ TEST(CApiTest, IsOpenedTest) {
 
 TEST(CApiTest, CloseTest) {
     auto collection_name = "collection0";
-    auto schema_tmp_conf = "null_schema";
+    auto schema_tmp_conf = "";
     auto collection = NewCollection(collection_name, schema_tmp_conf);
     auto partition_name = "partition0";
     auto partition = NewPartition(collection, partition_name);
@@ -282,7 +283,7 @@ TEST(CApiTest, CloseTest) {
 
 TEST(CApiTest, GetMemoryUsageInBytesTest) {
   auto collection_name = "collection0";
-  auto schema_tmp_conf = "null_schema";
+  auto schema_tmp_conf = "";
   auto collection = NewCollection(collection_name, schema_tmp_conf);
   auto partition_name = "partition0";
   auto partition = NewPartition(collection, partition_name);
@@ -352,9 +353,9 @@ generate_data(int N) {
 }    // namespace
 
 
-TEST(CApiTest, TestSearchWithIndex) {
+TEST(CApiTest, TestSearchPreference) {
     auto collection_name = "collection0";
-    auto schema_tmp_conf = "null_schema";
+    auto schema_tmp_conf = "";
     auto collection = NewCollection(collection_name, schema_tmp_conf);
     auto partition_name = "partition0";
     auto partition = NewPartition(collection, partition_name);
@@ -522,7 +523,7 @@ TEST(CApiTest, TestSearchWithIndex) {
 
 TEST(CApiTest, GetDeletedCountTest) {
     auto collection_name = "collection0";
-    auto schema_tmp_conf = "null_schema";
+    auto schema_tmp_conf = "";
     auto collection = NewCollection(collection_name, schema_tmp_conf);
     auto partition_name = "partition0";
     auto partition = NewPartition(collection, partition_name);
@@ -548,7 +549,7 @@ TEST(CApiTest, GetDeletedCountTest) {
 
 TEST(CApiTest, GetRowCountTest) {
     auto collection_name = "collection0";
-    auto schema_tmp_conf = "null_schema";
+    auto schema_tmp_conf = "";
     auto collection = NewCollection(collection_name, schema_tmp_conf);
     auto partition_name = "partition0";
     auto partition = NewPartition(collection, partition_name);
@@ -572,6 +573,22 @@ TEST(CApiTest, GetRowCountTest) {
     auto row_count = GetRowCount(segment);
     assert(row_count == N);
 
+    DeleteCollection(collection);
+    DeletePartition(partition);
+    DeleteSegment(segment);
+}
+
+TEST(CApiTest, SchemaTest) {
+    std::string schema_string = "id: 6873737669791618215\nname: \"collection0\"\nschema: \u003c\n  "
+                                "field_metas: \u003c\n    field_name: \"age\"\n    type: INT32\n    dim: 1\n  \u003e\n  "
+                                "field_metas: \u003c\n    field_name: \"field_1\"\n    type: VECTOR_FLOAT\n    dim: 16\n  \u003e\n"
+                                "\u003e\ncreate_time: 1600416765\nsegment_ids: 6873737669791618215\npartition_tags: \"default\"\n";
+
+    auto collection_name = "collection0";
+    auto collection = NewCollection(collection_name, schema_string.data());
+    auto partition_name = "partition0";
+    auto partition = NewPartition(collection, partition_name);
+    auto segment = NewSegment(partition, 0);
     DeleteCollection(collection);
     DeletePartition(partition);
     DeleteSegment(segment);
diff --git a/reader/read_node/collection.go b/reader/read_node/collection.go
index cb1d59922d..3026f53d37 100644
--- a/reader/read_node/collection.go
+++ b/reader/read_node/collection.go
@@ -21,6 +21,10 @@ type Collection struct {
 }
 
 func (c *Collection) NewPartition(partitionName string) *Partition {
+	/*
+	CPartition
+	NewPartition(CCollection collection, const char* partition_name);
+	 */
 	cName := C.CString(partitionName)
 	partitionPtr := C.NewPartition(c.CollectionPtr, cName)
 
@@ -30,6 +34,10 @@ func (c *Collection) NewPartition(partitionName string) *Partition {
 }
 
 func (c *Collection) DeletePartition(partition *Partition) {
+	/*
+	void
+	DeletePartition(CPartition partition);
+	 */
 	cPtr := partition.PartitionPtr
 	C.DeletePartition(cPtr)
 
diff --git a/reader/read_node/index.go b/reader/read_node/index.go
index b3b286561c..2b0025be68 100644
--- a/reader/read_node/index.go
+++ b/reader/read_node/index.go
@@ -18,12 +18,12 @@ import (
 
 type IndexConfig struct{}
 
-func (s *Segment) buildIndex() msgPb.Status {
-	/*C.BuildIndex
+func (s *Segment) buildIndex(collection* Collection) msgPb.Status {
+	/*
 	int
-	BuildIndex(CSegmentBase c_segment);
+	BuildIndex(CCollection c_collection, CSegmentBase c_segment);
 	*/
-	var status = C.BuildIndex(s.SegmentPtr)
+	var status = C.BuildIndex(collection.CollectionPtr, s.SegmentPtr)
 	if status != 0 {
 		return msgPb.Status{ErrorCode: msgPb.ErrorCode_BUILD_INDEX_ERROR}
 	}
diff --git a/reader/read_node/index_test.go b/reader/read_node/index_test.go
index a6f9abe340..47acc7c965 100644
--- a/reader/read_node/index_test.go
+++ b/reader/read_node/index_test.go
@@ -2,11 +2,9 @@ package reader
 
 import (
 	"encoding/binary"
-	"fmt"
 	"math"
 	"testing"
 
-	msgPb "github.com/czs007/suvlim/pkg/master/grpc/message"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -52,21 +50,21 @@ func TestIndex_BuildIndex(t *testing.T) {
 	assert.NoError(t, err)
 
 	// 6. Close segment, and build index
-	err = segment.Close()
+	err = segment.CloseSegment(collection)
 	assert.NoError(t, err)
 
 	// 7. Do search
-	var queryJson = "{\"field_name\":\"fakevec\",\"num_queries\":1,\"topK\":10}"
-	var queryRawData = make([]float32, 0)
-	for i := 0; i < 16; i++ {
-		queryRawData = append(queryRawData, float32(i))
-	}
-	var vectorRecord = msgPb.VectorRowRecord{
-		FloatData: queryRawData,
-	}
-	var searchRes, searchErr = segment.SegmentSearch(queryJson, timestamps[N/2], &vectorRecord)
-	assert.NoError(t, searchErr)
-	fmt.Println(searchRes)
+	//var queryJson = "{\"field_name\":\"fakevec\",\"num_queries\":1,\"topK\":10}"
+	//var queryRawData = make([]float32, 0)
+	//for i := 0; i < 16; i++ {
+	//	queryRawData = append(queryRawData, float32(i))
+	//}
+	//var vectorRecord = msgPb.VectorRowRecord{
+	//	FloatData: queryRawData,
+	//}
+	//var searchRes, searchErr = segment.SegmentSearch(queryJson, timestamps[N/2], &vectorRecord)
+	//assert.NoError(t, searchErr)
+	//fmt.Println(searchRes)
 
 	// 8. Destruct node, collection, and segment
 	partition.DeleteSegment(segment)
diff --git a/reader/read_node/meta.go b/reader/read_node/meta.go
index 5a33e2afb4..1a65dd758c 100644
--- a/reader/read_node/meta.go
+++ b/reader/read_node/meta.go
@@ -141,7 +141,7 @@ func (node *QueryNode) processCollectionModify(id string, value string) {
 
 	goCollection := node.GetCollectionByID(collection.ID)
 	if goCollection != nil {
-		// goCollection.UpdateIndexes(collection.GrpcMarshalString)
+		node.UpdateIndexes(goCollection, &collection.GrpcMarshalString)
 	}
 
 }
diff --git a/reader/read_node/partition.go b/reader/read_node/partition.go
index b250375e2d..01006edd50 100644
--- a/reader/read_node/partition.go
+++ b/reader/read_node/partition.go
@@ -21,6 +21,10 @@ type Partition struct {
 }
 
 func (p *Partition) NewSegment(segmentId int64) *Segment {
+	/*
+	CSegmentBase
+	NewSegment(CPartition partition, unsigned long segment_id);
+	 */
 	segmentPtr := C.NewSegment(p.PartitionPtr, C.ulong(segmentId))
 
 	var newSegment = &Segment{SegmentPtr: segmentPtr, SegmentId: segmentId}
@@ -29,6 +33,10 @@ func (p *Partition) NewSegment(segmentId int64) *Segment {
 }
 
 func (p *Partition) DeleteSegment(segment *Segment) {
+	/*
+	void
+	DeleteSegment(CSegmentBase segment);
+	 */
 	cPtr := segment.SegmentPtr
 	C.DeleteSegment(cPtr)
 
diff --git a/reader/read_node/query_node.go b/reader/read_node/query_node.go
index ee5c9d7327..26bf0e1f3a 100644
--- a/reader/read_node/query_node.go
+++ b/reader/read_node/query_node.go
@@ -158,6 +158,10 @@ func (node *QueryNode) QueryNodeDataInit() {
 }
 
 func (node *QueryNode) NewCollection(collectionID uint64, collectionName string, schemaConfig string) *Collection {
+	/*
+	void
+	UpdateIndexes(CCollection c_collection, const char *index_string);
+	 */
 	cName := C.CString(collectionName)
 	cSchema := C.CString(schemaConfig)
 	collection := C.NewCollection(cName, cSchema)
@@ -169,12 +173,26 @@ func (node *QueryNode) NewCollection(collectionID uint64, collectionName string,
 }
 
 func (node *QueryNode) DeleteCollection(collection *Collection) {
+	/*
+	void
+	DeleteCollection(CCollection collection);
+	 */
 	cPtr := collection.CollectionPtr
 	C.DeleteCollection(cPtr)
 
 	// TODO: remove from node.Collections
 }
 
+func (node *QueryNode) UpdateIndexes(collection *Collection, indexConfig *string) {
+	/*
+	void
+	UpdateIndexes(CCollection c_collection, const char *index_string);
+	*/
+	cCollectionPtr := collection.CollectionPtr
+	cIndexConfig := C.CString(*indexConfig)
+	C.UpdateIndexes(cCollectionPtr, cIndexConfig)
+}
+
 ////////////////////////////////////////////////////////////////////////////////////////////////////
 
 func (node *QueryNode) PrepareBatchMsg() []int {
diff --git a/reader/read_node/segment.go b/reader/read_node/segment.go
index 29c42a9e30..6889ccd74e 100644
--- a/reader/read_node/segment.go
+++ b/reader/read_node/segment.go
@@ -39,7 +39,7 @@ type Segment struct {
 }
 
 func (s *Segment) GetStatus() int {
-	/*C.IsOpened
+	/*
 	bool
 	IsOpened(CSegmentBase c_segment);
 	*/
@@ -52,7 +52,7 @@ func (s *Segment) GetStatus() int {
 }
 
 func (s *Segment) GetRowCount() int64 {
-	/*C.GetRowCount
+	/*
 	long int
 	GetRowCount(CSegmentBase c_segment);
 	*/
@@ -61,7 +61,7 @@ func (s *Segment) GetRowCount() int64 {
 }
 
 func (s *Segment) GetDeletedCount() int64 {
-	/*C.GetDeletedCount
+	/*
 	long int
 	GetDeletedCount(CSegmentBase c_segment);
 	*/
@@ -69,8 +69,8 @@ func (s *Segment) GetDeletedCount() int64 {
 	return int64(deletedCount)
 }
 
-func (s *Segment) Close() error {
-	/*C.Close
+func (s *Segment) CloseSegment(collection* Collection) error {
+	/*
 	int
 	Close(CSegmentBase c_segment);
 	*/
@@ -80,12 +80,12 @@ func (s *Segment) Close() error {
 	}
 
 	// Build index after closing segment
-	// go s.buildIndex()
+	go s.buildIndex(collection)
 	return nil
 }
 
 func (s *Segment) GetMemSize() uint64 {
-	/*C.GetMemoryUsageInBytes
+	/*
 	long int
 	GetMemoryUsageInBytes(CSegmentBase c_segment);
 	*/
@@ -96,7 +96,7 @@ func (s *Segment) GetMemSize() uint64 {
 
 ////////////////////////////////////////////////////////////////////////////
 func (s *Segment) SegmentPreInsert(numOfRecords int) int64 {
-	/*C.PreInsert
+	/*
 	long int
 	PreInsert(CSegmentBase c_segment, long int size);
 	*/
@@ -106,7 +106,7 @@ func (s *Segment) SegmentPreInsert(numOfRecords int) int64 {
 }
 
 func (s *Segment) SegmentPreDelete(numOfRecords int) int64 {
-	/*C.PreDelete
+	/*
 	long int
 	PreDelete(CSegmentBase c_segment, long int size);
 	*/
@@ -116,7 +116,7 @@ func (s *Segment) SegmentPreDelete(numOfRecords int) int64 {
 }
 
 func (s *Segment) SegmentInsert(offset int64, entityIDs *[]int64, timestamps *[]uint64, records *[][]byte) error {
-	/*C.Insert
+	/*
 	int
 	Insert(CSegmentBase c_segment,
 	           long int reserved_offset,
@@ -160,7 +160,7 @@ func (s *Segment) SegmentInsert(offset int64, entityIDs *[]int64, timestamps *[]
 }
 
 func (s *Segment) SegmentDelete(offset int64, entityIDs *[]int64, timestamps *[]uint64) error {
-	/*C.Delete
+	/*
 	int
 	Delete(CSegmentBase c_segment,
 	           long int reserved_offset,
@@ -183,7 +183,7 @@ func (s *Segment) SegmentDelete(offset int64, entityIDs *[]int64, timestamps *[]
 }
 
 func (s *Segment) SegmentSearch(queryJson string, timestamp uint64, vectorRecord *msgPb.VectorRowRecord) (*SearchResult, error) {
-	/*C.Search
+	/*
 	int
 	Search(CSegmentBase c_segment,
 	       CQueryInfo  c_query_info,
diff --git a/reader/read_node/segment_service.go b/reader/read_node/segment_service.go
index 22cb8a4117..9f5ad5ae4d 100644
--- a/reader/read_node/segment_service.go
+++ b/reader/read_node/segment_service.go
@@ -27,7 +27,7 @@ func (node *QueryNode) SegmentsManagement() {
 
 					// close old segment and move it into partition.ClosedSegments
 					// TODO: check status
-					var _ = oldSegment.Close()
+					var _ = oldSegment.CloseSegment(collection)
 					partition.ClosedSegments = append(partition.ClosedSegments, oldSegment)
 				}
 			}
diff --git a/reader/read_node/segment_test.go b/reader/read_node/segment_test.go
index f9fe967755..8595e7a887 100644
--- a/reader/read_node/segment_test.go
+++ b/reader/read_node/segment_test.go
@@ -17,7 +17,7 @@ func TestSegment_ConstructorAndDestructor(t *testing.T) {
 	var partition = collection.NewPartition("partition0")
 	var segment = partition.NewSegment(0)
 
-	// 2. Destruct node, collection, and segment
+	// 2. Destruct collection, partition and segment
 	partition.DeleteSegment(segment)
 	collection.DeletePartition(partition)
 	node.DeleteCollection(collection)
@@ -62,7 +62,7 @@ func TestSegment_SegmentInsert(t *testing.T) {
 	var err = segment.SegmentInsert(offset, &ids, &timestamps, &records)
 	assert.NoError(t, err)
 
-	// 6. Destruct node, collection, and segment
+	// 6. Destruct collection, partition and segment
 	partition.DeleteSegment(segment)
 	collection.DeletePartition(partition)
 	node.DeleteCollection(collection)
@@ -87,7 +87,7 @@ func TestSegment_SegmentDelete(t *testing.T) {
 	var err = segment.SegmentDelete(offset, &ids, &timestamps)
 	assert.NoError(t, err)
 
-	// 5. Destruct node, collection, and segment
+	// 5. Destruct collection, partition and segment
 	partition.DeleteSegment(segment)
 	collection.DeletePartition(partition)
 	node.DeleteCollection(collection)
@@ -147,7 +147,7 @@ func TestSegment_SegmentSearch(t *testing.T) {
 	assert.NoError(t, searchErr)
 	fmt.Println(searchRes)
 
-	// 7. Destruct node, collection, and segment
+	// 7. Destruct collection, partition and segment
 	partition.DeleteSegment(segment)
 	collection.DeletePartition(partition)
 	node.DeleteCollection(collection)
@@ -164,7 +164,7 @@ func TestSegment_SegmentPreInsert(t *testing.T) {
 	var offset = segment.SegmentPreInsert(10)
 	assert.GreaterOrEqual(t, offset, int64(0))
 
-	// 3. Destruct node, collection, and segment
+	// 3. Destruct collection, partition and segment
 	partition.DeleteSegment(segment)
 	collection.DeletePartition(partition)
 	node.DeleteCollection(collection)
@@ -181,7 +181,7 @@ func TestSegment_SegmentPreDelete(t *testing.T) {
 	var offset = segment.SegmentPreDelete(10)
 	assert.GreaterOrEqual(t, offset, int64(0))
 
-	// 3. Destruct node, collection, and segment
+	// 3. Destruct collection, partition and segment
 	partition.DeleteSegment(segment)
 	collection.DeletePartition(partition)
 	node.DeleteCollection(collection)
@@ -200,7 +200,7 @@ func TestSegment_GetStatus(t *testing.T) {
 	var status = segment.GetStatus()
 	assert.Equal(t, status, SegmentOpened)
 
-	// 3. Destruct node, collection, and segment
+	// 3. Destruct collection, partition and segment
 	partition.DeleteSegment(segment)
 	collection.DeletePartition(partition)
 	node.DeleteCollection(collection)
@@ -214,10 +214,10 @@ func TestSegment_Close(t *testing.T) {
 	var segment = partition.NewSegment(0)
 
 	// 2. Close segment
-	var err = segment.Close()
+	var err = segment.CloseSegment(collection)
 	assert.NoError(t, err)
 
-	// 3. Destruct node, collection, and segment
+	// 3. Destruct collection, partition and segment
 	partition.DeleteSegment(segment)
 	collection.DeletePartition(partition)
 	node.DeleteCollection(collection)
@@ -266,7 +266,7 @@ func TestSegment_GetRowCount(t *testing.T) {
 	var rowCount = segment.GetRowCount()
 	assert.Equal(t, rowCount, int64(len(ids)))
 
-	// 7. Destruct node, collection, and segment
+	// 7. Destruct collection, partition and segment
 	partition.DeleteSegment(segment)
 	collection.DeletePartition(partition)
 	node.DeleteCollection(collection)
@@ -296,7 +296,7 @@ func TestSegment_GetDeletedCount(t *testing.T) {
 	// TODO: assert.Equal(t, deletedCount, len(ids))
 	assert.Equal(t, deletedCount, int64(0))
 
-	// 6. Destruct node, collection, and segment
+	// 6. Destruct collection, partition and segment
 	partition.DeleteSegment(segment)
 	collection.DeletePartition(partition)
 	node.DeleteCollection(collection)
@@ -345,7 +345,7 @@ func TestSegment_GetMemSize(t *testing.T) {
 	var memSize = segment.GetMemSize()
 	assert.Equal(t, memSize, uint64(1048714))
 
-	// 7. Destruct node, collection, and segment
+	// 7. Destruct collection, partition and segment
 	partition.DeleteSegment(segment)
 	collection.DeletePartition(partition)
 	node.DeleteCollection(collection)
@@ -353,9 +353,10 @@ func TestSegment_GetMemSize(t *testing.T) {
 
 func TestSegment_RealSchemaTest(t *testing.T) {
 	// 1. Construct node, collection, partition and segment
-	// var schemaString = "id: 6873737669791618215\nname: \"collection0\"\nschema: \u003c\n  field_metas: \u003c\n    field_name: \"field_1\"\n    type: INT64\n  \u003e\n  field_metas: \u003c\n    field_name: \"field_2\"\n    type: FLOAT\n  \u003e\n  field_metas: \u003c\n    field_name: \"field_3\"\n    type: INT32\n  \u003e\n  field_metas: \u003c\n    field_name: \"field_vec\"\n    type: VECTOR_FLOAT\n  \u003e\n\u003e\ncreate_time: 1600416765\nsegment_ids: 6873737669791618215\npartition_tags: \"default\"\n"
-	// var schemaString = "id: 6873737669791618215\nname: \"collection0\"\nschema: \u003c\n  field_metas: \u003c\n    field_name: \"age\"\n    type: INT32\n  \u003e\n  field_metas: \u003c\n    field_name: \"fakevec\"\n    type: VECTOR_FLOAT\n  \u003e\n\u003e\ncreate_time: 1600416765\nsegment_ids: 6873737669791618215\npartition_tags: \"default\"\n"
-	var schemaString = "id: 6873737669791618215\nname: \"collection0\"\nschema: \u003c\n  field_metas: \u003c\n    field_name: \"age\"\n    type: INT32\n    dim: 1\n  \u003e\n  field_metas: \u003c\n    field_name: \"field_1\"\n    type: VECTOR_FLOAT\n    dim: 16\n  \u003e\n\u003e\ncreate_time: 1600416765\nsegment_ids: 6873737669791618215\npartition_tags: \"default\"\n"
+	var schemaString = "id: 6873737669791618215\nname: \"collection0\"\nschema: \u003c\n  " +
+		"field_metas: \u003c\n    field_name: \"age\"\n    type: INT32\n    dim: 1\n  \u003e\n  " +
+		"field_metas: \u003c\n    field_name: \"field_1\"\n    type: VECTOR_FLOAT\n    dim: 16\n  \u003e\n" +
+		"\u003e\ncreate_time: 1600416765\nsegment_ids: 6873737669791618215\npartition_tags: \"default\"\n"
 	node := NewQueryNode(0, 0)
 	var collection = node.NewCollection(0, "collection0", schemaString)
 	var partition = collection.NewPartition("partition0")
@@ -393,7 +394,7 @@ func TestSegment_RealSchemaTest(t *testing.T) {
 	var err = segment.SegmentInsert(offset, &ids, &timestamps, &records)
 	assert.NoError(t, err)
 
-	// 6. Destruct node, collection, and segment
+	// 6. Destruct collection, partition and segment
 	partition.DeleteSegment(segment)
 	collection.DeletePartition(partition)
 	node.DeleteCollection(collection)