diff --git a/test/base/milvus_client.go b/test/base/milvus_client.go
index a5835ae0..bb94dd2a 100644
--- a/test/base/milvus_client.go
+++ b/test/base/milvus_client.go
@@ -198,6 +198,14 @@ func (mc *MilvusClient) HasCollection(ctx context.Context, collName string) (boo
 	return has, err
 }
 
+// AlterCollection changes collection attributes
+func (mc *MilvusClient) AlterCollection(ctx context.Context, collName string, attrs ...entity.CollectionAttribute) error {
+	preRequest("AlterCollection", ctx, collName)
+	err := mc.mClient.AlterCollection(ctx, collName, attrs...)
+	postResponse("AlterCollection", err)
+	return err
+}
+
 // -- alias --
 
 // CreateAlias Create Alias
@@ -356,6 +364,14 @@ func (mc *MilvusClient) GetIndexState(ctx context.Context, collName string, fiel
 	return indexState, err
 }
 
+// AlterIndex modifies the index params.
+func (mc *MilvusClient) AlterIndex(ctx context.Context, collName string, indexName string, opts ...client.IndexOption) error {
+	preRequest("AlterIndex", ctx, collName, indexName, opts)
+	err := mc.mClient.AlterIndex(ctx, collName, indexName, opts...)
+	postResponse("AlterIndex", err)
+	return err
+}
+
 // -- basic operation --
 
 // Insert insert data
diff --git a/test/testcases/load_release_test.go b/test/testcases/load_release_test.go
index dc04b0b1..9354baf2 100644
--- a/test/testcases/load_release_test.go
+++ b/test/testcases/load_release_test.go
@@ -5,9 +5,12 @@ package testcases
 import (
 	"fmt"
 	"log"
+	"strconv"
 	"testing"
 	"time"
 
+	"github.com/milvus-io/milvus-sdk-go/v2/client"
+
 	"github.com/milvus-io/milvus-sdk-go/v2/entity"
 
 	"github.com/stretchr/testify/require"
@@ -512,3 +515,305 @@ func TestReleaseMultiPartitions(t *testing.T) {
 		[]string{common.DefaultIntFieldName})
 	common.CheckErr(t, errQuery, false, "collection not loaded")
 }
+
+// test mmap collection raw data and index
+// create -> insert -> flush -> index with mmap -> load -> alter collection with mmap -> reload -> read op
+func TestMmapCollectionIndexDefault(t *testing.T) {
+	ctx := createContext(t, time.Second*common.DefaultTimeout*2)
+	// connect
+	mc := createMilvusClient(ctx, t)
+
+	// create -> insert [0, 3000) -> flush
+	cp := CollectionParams{CollectionFieldsType: AllFields, AutoID: false, EnableDynamicField: true,
+		ShardsNum: common.DefaultShards, Dim: common.DefaultDim}
+	collName := createCollection(ctx, t, mc, cp)
+
+	dp := DataParams{DoInsert: true, CollectionName: collName, CollectionFieldsType: AllFields, start: 0,
+		nb: common.DefaultNb, dim: common.DefaultDim, EnableDynamicField: true}
+	insertData(ctx, t, mc, dp)
+	_ = mc.Flush(ctx, collName, false)
+
+	// create vector index with mmap
+	GenDefaultIndexParamsForAllVectors()
+	indexHnsw, _ := entity.NewIndexHNSW(entity.L2, 8, 96)
+	indexBinary, _ := entity.NewIndexBinIvfFlat(entity.JACCARD, 64)
+	for _, fieldName := range common.AllVectorsFieldsName {
+		if fieldName == common.DefaultBinaryVecFieldName {
+			err := mc.CreateIndex(ctx, collName, fieldName, indexBinary, false, client.WithMmap(true))
+			common.CheckErr(t, err, true)
+		} else if fieldName == common.DefaultFloatVecFieldName {
+			err := mc.CreateIndex(ctx, collName, fieldName, indexHnsw, false, client.WithMmap(true))
+			common.CheckErr(t, err, true)
+		} else {
+			err := mc.CreateIndex(ctx, collName, fieldName, indexHnsw, false)
+			common.CheckErr(t, err, true)
+		}
+	}
+
+	// describe index and check mmap
+	for _, fieldName := range common.AllVectorsFieldsName {
+		if fieldName == common.DefaultFloatVecFieldName || fieldName == common.DefaultBinaryVecFieldName {
+			indexes, _ := mc.DescribeIndex(ctx, collName, fieldName)
+			require.Len(t, indexes, 1)
+			// check index mmap
+			require.Equal(t, "true", indexes[0].Params()["mmap.enabled"])
+		}
+	}
+
+	// load collection -> describe collection and check mmap false
+	_ = mc.LoadCollection(ctx, collName, false)
+	coll, _ := mc.DescribeCollection(ctx, collName)
+	require.Equal(t, "", coll.Properties["mmap.enabled"])
+
+	// alter collection and check collection mmap
+	_ = mc.ReleaseCollection(ctx, collName)
+	err := mc.AlterCollection(ctx, collName, entity.Mmap(true))
+	common.CheckErr(t, err, true)
+
+	//describe collection
+	mc.LoadCollection(ctx, collName, false)
+	coll, _ = mc.DescribeCollection(ctx, collName)
+	require.Equal(t, "true", coll.Properties["mmap.enabled"])
+
+	// query
+	queryRes, err := mc.Query(ctx, collName, []string{}, fmt.Sprintf("%s < 10", common.DefaultIntFieldName), []string{"*"})
+	common.CheckErr(t, err, true)
+	require.Equal(t, queryRes.GetColumn(common.DefaultIntFieldName).Len(), 10)
+	common.CheckOutputFields(t, queryRes, common.GetAllFieldsName(true, false))
+
+	// search
+	queryVec1 := common.GenSearchVectors(common.DefaultNq, common.DefaultDim, entity.FieldTypeFloatVector)
+	sp, _ := entity.NewIndexHNSWSearchParam(74)
+	expr := fmt.Sprintf("%s > 10", common.DefaultIntFieldName)
+	searchRes, _ := mc.Search(ctx, collName, []string{}, expr, []string{"*"}, queryVec1, common.DefaultFloatVecFieldName,
+		entity.L2, common.DefaultTopK, sp)
+	common.CheckOutputFields(t, searchRes[0].Fields, common.GetAllFieldsName(true, false))
+
+	// hybrid search
+	queryVec2 := common.GenSearchVectors(common.DefaultNq, common.DefaultDim, entity.FieldTypeBinaryVector)
+	sReqs := []*client.ANNSearchRequest{
+		client.NewANNSearchRequest(common.DefaultFloatVecFieldName, entity.L2, "", queryVec1, sp, common.DefaultTopK, client.WithOffset(3)),
+		client.NewANNSearchRequest(common.DefaultBinaryVecFieldName, entity.JACCARD, "", queryVec2, sp, common.DefaultTopK),
+	}
+	_, errSearch := mc.HybridSearch(ctx, collName, []string{}, common.DefaultTopK, []string{}, client.NewRRFReranker(), sReqs)
+	common.CheckErr(t, errSearch, true)
+}
+
+// test mmap collection raw data and index
+// create -> insert -> flush -> index -> load -> alter collection with mmap -> alter index with mmap -> reload -> read op
+func TestMmapAlterCollectionIndexDefault(t *testing.T) {
+	ctx := createContext(t, time.Second*common.DefaultTimeout*2)
+	// connect
+	mc := createMilvusClient(ctx, t)
+
+	// create -> insert [0, 3000) -> flush
+	cp := CollectionParams{CollectionFieldsType: AllFields, AutoID: false, EnableDynamicField: true,
+		ShardsNum: common.DefaultShards, Dim: common.DefaultDim}
+
+	dp := DataParams{DoInsert: true, CollectionFieldsType: AllFields, start: 0,
+		nb: common.DefaultNb, dim: common.DefaultDim, EnableDynamicField: true}
+
+	ips := GenDefaultIndexParamsForAllVectors()
+	collName := prepareCollection(ctx, t, mc, cp, WithDataParams(dp), WithIndexParams(ips), WithCreateOption(client.WithConsistencyLevel(entity.ClStrong)))
+
+	// describe index and check mmap
+	for _, fieldName := range common.AllVectorsFieldsName {
+		indexes, _ := mc.DescribeIndex(ctx, collName, fieldName)
+		// check index mmap
+		require.Equal(t, "", indexes[0].Params()["mmap.enabled"])
+	}
+
+	//describe collection
+	mc.LoadCollection(ctx, collName, false)
+	coll, _ := mc.DescribeCollection(ctx, collName)
+	require.Equal(t, "", coll.Properties["mmap.enabled"])
+
+	// alter mmap: collection and index
+	_ = mc.ReleaseCollection(ctx, collName)
+	err := mc.AlterCollection(ctx, collName, entity.Mmap(true))
+	common.CheckErr(t, err, true)
+	for _, fieldName := range common.AllVectorsFieldsName {
+		err := mc.AlterIndex(ctx, collName, fieldName, client.WithMmap(true))
+		common.CheckErr(t, err, true)
+	}
+
+	// load collection -> describe collection and check mmap false
+	//describe collection
+	mc.LoadCollection(ctx, collName, false)
+	coll, _ = mc.DescribeCollection(ctx, collName)
+	require.Equal(t, "true", coll.Properties["mmap.enabled"])
+	for _, fieldName := range common.AllVectorsFieldsName {
+		idx, _ := mc.DescribeIndex(ctx, collName, fieldName)
+		require.Equal(t, "true", idx[0].Params()["mmap.enabled"])
+	}
+
+	// query
+	queryRes, err := mc.Query(ctx, collName, []string{}, fmt.Sprintf("%s < 10", common.DefaultIntFieldName), []string{"*"})
+	common.CheckErr(t, err, true)
+	require.Equal(t, queryRes.GetColumn(common.DefaultIntFieldName).Len(), 10)
+	common.CheckOutputFields(t, queryRes, common.GetAllFieldsName(true, false))
+
+	// search
+	queryVec1 := common.GenSearchVectors(common.DefaultNq, common.DefaultDim, entity.FieldTypeFloatVector)
+	sp, _ := entity.NewIndexHNSWSearchParam(74)
+	expr := fmt.Sprintf("%s > 10", common.DefaultIntFieldName)
+	searchRes, _ := mc.Search(ctx, collName, []string{}, expr, []string{"*"}, queryVec1, common.DefaultFloatVecFieldName,
+		entity.L2, common.DefaultTopK, sp)
+	common.CheckOutputFields(t, searchRes[0].Fields, common.GetAllFieldsName(true, false))
+
+	// hybrid search
+	queryVec2 := common.GenSearchVectors(common.DefaultNq, common.DefaultDim, entity.FieldTypeBinaryVector)
+	sReqs := []*client.ANNSearchRequest{
+		client.NewANNSearchRequest(common.DefaultFloatVecFieldName, entity.L2, "", queryVec1, sp, common.DefaultTopK, client.WithOffset(3)),
+		client.NewANNSearchRequest(common.DefaultBinaryVecFieldName, entity.JACCARD, "", queryVec2, sp, common.DefaultTopK),
+	}
+	_, errSearch := mc.HybridSearch(ctx, collName, []string{}, common.DefaultTopK, []string{}, client.NewRRFReranker(), sReqs)
+	common.CheckErr(t, errSearch, true)
+}
+
+// test mmap collection loaded
+func TestMmapCollectionLoaded(t *testing.T) {
+	ctx := createContext(t, time.Second*common.DefaultTimeout*2)
+	// connect
+	mc := createMilvusClient(ctx, t)
+
+	// create -> insert -> flush -> index -> load
+	cp := CollectionParams{CollectionFieldsType: Int64FloatVec, AutoID: false, EnableDynamicField: false,
+		ShardsNum: common.DefaultShards, Dim: common.DefaultDim}
+
+	dp := DataParams{DoInsert: true, CollectionFieldsType: Int64FloatVec, start: 0, nb: common.DefaultNb,
+		dim: common.DefaultDim, EnableDynamicField: false}
+
+	collName := prepareCollection(ctx, t, mc, cp, WithDataParams(dp), WithCreateOption(client.WithConsistencyLevel(entity.ClStrong)))
+
+	// mmap collection raw data
+	err := mc.AlterCollection(ctx, collName, entity.Mmap(true))
+	common.CheckErr(t, err, false, "can not alter mmap properties if collection loaded")
+
+	// mmap index
+	err = mc.AlterIndex(ctx, collName, common.DefaultFloatVecFieldName, client.WithMmap(true))
+	common.CheckErr(t, err, false, "can't alter index on loaded collection, please release the collection first")
+}
+
+// test mmap collection which scalar field indexed
+func TestMmapCollectionScalarIndexed(t *testing.T) {
+	ctx := createContext(t, time.Second*common.DefaultTimeout*2)
+	// connect
+	mc := createMilvusClient(ctx, t)
+
+	// create -> insert -> flush -> index -> load
+	cp := CollectionParams{CollectionFieldsType: Int64FloatVec, AutoID: false, EnableDynamicField: false,
+		ShardsNum: common.DefaultShards, Dim: common.DefaultDim}
+
+	dp := DataParams{DoInsert: true, CollectionFieldsType: Int64FloatVec, start: 0, nb: common.DefaultNb,
+		dim: common.DefaultDim, EnableDynamicField: false}
+
+	collName := prepareCollection(ctx, t, mc, cp, WithDataParams(dp), WithCreateOption(client.WithConsistencyLevel(entity.ClStrong)))
+
+	// create scalar index
+	for _, fName := range []string{common.DefaultIntFieldName, common.DefaultFloatFieldName} {
+		err := mc.CreateIndex(ctx, collName, fName, entity.NewScalarIndexWithType(entity.Inverted), false)
+		common.CheckErr(t, err, true)
+	}
+
+	// mmap collection
+	mc.ReleaseCollection(ctx, collName)
+	err := mc.AlterCollection(ctx, collName, entity.Mmap(true))
+	common.CheckErr(t, err, true)
+	err = mc.LoadCollection(ctx, collName, false)
+	common.CheckErr(t, err, true)
+}
+
+// test mmap unsupported index: DiskANN, GPU-class
+func TestMmapIndexUnsupported(t *testing.T) {
+	t.Skip("https://github.com/milvus-io/milvus-sdk-go/issues/714")
+	ctx := createContext(t, time.Second*common.DefaultTimeout*2)
+	// connect
+	mc := createMilvusClient(ctx, t)
+
+	// create -> insert -> flush -> index -> load
+	cp := CollectionParams{CollectionFieldsType: Int64FloatVec, AutoID: false, EnableDynamicField: false,
+		ShardsNum: common.DefaultShards, Dim: common.DefaultDim}
+	collName := createCollection(ctx, t, mc, cp)
+
+	dp := DataParams{DoInsert: true, CollectionName: collName, CollectionFieldsType: Int64FloatVec, start: 0,
+		nb: common.DefaultNb, dim: common.DefaultDim, EnableDynamicField: false}
+	insertData(ctx, t, mc, dp)
+	mc.Flush(ctx, collName, false)
+
+	//create index with mmap
+	idx, _ := entity.NewIndexDISKANN(entity.COSINE)
+	err := mc.CreateIndex(ctx, collName, common.DefaultFloatVecFieldName, idx, false, client.WithMmap(true))
+	common.CheckErr(t, err, false, "index type DISKANN does not support mmap")
+
+	//create scalar index with mmap
+	for _, idx := range []entity.Index{entity.NewScalarIndex(), entity.NewScalarIndexWithType(entity.Inverted)} {
+		err := mc.CreateIndex(ctx, collName, common.DefaultFloatFieldName, idx, false, client.WithMmap(true))
+		common.CheckErr(t, err, false, "does not support mmap")
+	}
+}
+
+func TestAlterIndexMmapUnsupportedIndex(t *testing.T) {
+	ctx := createContext(t, time.Second*common.DefaultTimeout*2)
+	// connect
+	mc := createMilvusClient(ctx, t)
+
+	// create -> insert -> flush -> index -> load
+	cp := CollectionParams{CollectionFieldsType: Int64FloatVec, AutoID: false, EnableDynamicField: false,
+		ShardsNum: common.DefaultShards, Dim: common.DefaultDim}
+	collName := createCollection(ctx, t, mc, cp)
+
+	dp := DataParams{DoInsert: true, CollectionName: collName, CollectionFieldsType: Int64FloatVec, start: 0,
+		nb: common.DefaultNb, dim: common.DefaultDim, EnableDynamicField: false}
+	insertData(ctx, t, mc, dp)
+	mc.Flush(ctx, collName, false)
+
+	idxHnsw, _ := entity.NewIndexDISKANN(entity.IP)
+	err := mc.CreateIndex(ctx, collName, common.DefaultFloatVecFieldName, idxHnsw, false)
+	common.CheckErr(t, err, true)
+	for _, mmap := range []bool{true, false} {
+		err = mc.AlterIndex(ctx, collName, common.DefaultFloatVecFieldName, client.WithMmap(mmap))
+		common.CheckErr(t, err, false, "index type DISKANN does not support mmap: invalid parameter")
+	}
+}
+
+func TestMmapAlterIndex(t *testing.T) {
+	t.Parallel()
+	for _, mmap := range []bool{true, false} {
+		ctx := createContext(t, time.Second*common.DefaultTimeout*2)
+		// connect
+		mc := createMilvusClient(ctx, t)
+
+		// create -> insert -> flush -> index -> load
+		cp := CollectionParams{CollectionFieldsType: Int64FloatVec, AutoID: false, EnableDynamicField: false,
+			ShardsNum: common.DefaultShards, Dim: common.DefaultDim}
+		collName := createCollection(ctx, t, mc, cp)
+
+		dp := DataParams{DoInsert: true, CollectionName: collName, CollectionFieldsType: Int64FloatVec, start: 0,
+			nb: common.DefaultNb, dim: common.DefaultDim, EnableDynamicField: false}
+		insertData(ctx, t, mc, dp)
+		mc.Flush(ctx, collName, false)
+
+		// create index and enable mmap
+		idxHnsw, _ := entity.NewIndexHNSW(entity.COSINE, 8, 96)
+		err := mc.CreateIndex(ctx, collName, common.DefaultFloatVecFieldName, idxHnsw, false, client.WithMmap(!mmap))
+		common.CheckErr(t, err, true)
+
+		// alter index and enable mmap
+		err = mc.AlterIndex(ctx, collName, common.DefaultFloatVecFieldName, client.WithMmap(mmap))
+		common.CheckErr(t, err, true)
+
+		idx, _ := mc.DescribeIndex(ctx, collName, common.DefaultFloatVecFieldName)
+		require.Equal(t, strconv.FormatBool(mmap), idx[0].Params()["mmap.enabled"])
+
+		err = mc.LoadCollection(ctx, collName, false)
+		common.CheckErr(t, err, true)
+
+		queryVec1 := common.GenSearchVectors(common.DefaultNq, common.DefaultDim, entity.FieldTypeFloatVector)
+		sp, _ := entity.NewIndexHNSWSearchParam(74)
+		expr := fmt.Sprintf("%s > 10", common.DefaultIntFieldName)
+		searchRes, _ := mc.Search(ctx, collName, []string{}, expr, []string{"*"}, queryVec1, common.DefaultFloatVecFieldName,
+			entity.COSINE, common.DefaultTopK, sp)
+		common.CheckOutputFields(t, searchRes[0].Fields, []string{common.DefaultIntFieldName, common.DefaultFloatFieldName, common.DefaultFloatVecFieldName})
+	}
+}