diff --git a/configs/advanced/data_node.yaml b/configs/advanced/data_node.yaml
index 621478c437..f8596a88b3 100644
--- a/configs/advanced/data_node.yaml
+++ b/configs/advanced/data_node.yaml
@@ -18,4 +18,6 @@ dataNode:
 
   flush:
     # max buffer size to flush
-    insertBufSize: 32000 # number of rows
+    insertBufSize: 32000 # GOOSE TODO: to delete
+
+    # insertBufSize: 16 # MB GOOSE TODO: to enable
diff --git a/internal/datanode/flow_graph_insert_buffer_node.go b/internal/datanode/flow_graph_insert_buffer_node.go
index 6466303c1d..2a2cf41cae 100644
--- a/internal/datanode/flow_graph_insert_buffer_node.go
+++ b/internal/datanode/flow_graph_insert_buffer_node.go
@@ -54,10 +54,12 @@ type insertBufferNode struct {
 	BaseNode
 	channelName  string
 	insertBuffer *insertBuffer
-	replica      Replica
-	idAllocator  allocatorInterface
-	flushMap     sync.Map
-	flushChan    <-chan *flushMsg
+	// insertBuffer map[UniqueID]*BufferData // SegmentID to BufferData
+	replica     Replica
+	idAllocator allocatorInterface
+
+	flushMap  sync.Map
+	flushChan <-chan *flushMsg
 
 	minIOKV kv.BaseKV
 
@@ -81,6 +83,22 @@ type segmentFlushUnit struct {
 	flushed        bool
 }
 
+type BufferData struct {
+	buffer *InsertData
+	size   int64
+	limit  int64 // Num of rows
+}
+
+func newBufferData(dimension int64) (*BufferData, error) {
+	if dimension == 0 {
+		return nil, errors.New("Invalid dimension")
+	}
+
+	limit := Params.FlushInsertBufferSize * (1 << 18) / dimension
+
+	return &BufferData{&InsertData{}, 0, limit}, nil
+}
+
 type insertBuffer struct {
 	insertData map[UniqueID]*InsertData // SegmentID to InsertData
 	maxSize    int64
@@ -199,7 +217,7 @@ func (ibNode *insertBufferNode) Operate(in []Msg) []Msg {
 
 	// insert messages -> buffer
 	for _, msg := range iMsg.insertMessages {
-		err := ibNode.bufferInsertMsg(iMsg, msg)
+		err := ibNode.bufferInsertMsg(msg, endPositions[0])
 		if err != nil {
 			log.Warn("msg to buffer failed", zap.Error(err))
 		}
@@ -383,7 +401,7 @@ func (ibNode *insertBufferNode) updateSegStatesInReplica(insertMsgs []*msgstream
 // 	1.2 Get buffer data and put data into each field buffer
 // 	1.3 Put back into buffer
 // 	1.4 Update related statistics
-func (ibNode *insertBufferNode) bufferInsertMsg(iMsg *insertMsg, msg *msgstream.InsertMsg) error {
+func (ibNode *insertBufferNode) bufferInsertMsg(msg *msgstream.InsertMsg, endPos *internalpb.MsgPosition) error {
 	if len(msg.RowIDs) != len(msg.Timestamps) || len(msg.RowIDs) != len(msg.RowData) {
 		return errors.New("misaligned messages detected")
 	}
@@ -625,13 +643,8 @@ func (ibNode *insertBufferNode) bufferInsertMsg(iMsg *insertMsg, msg *msgstream.
 	ibNode.insertBuffer.insertData[currentSegID] = idata
 
 	// store current endPositions as Segment->EndPostion
-	endPositions := make([]*internalpb.MsgPosition, 0, len(iMsg.endPositions))
-	for idx := range iMsg.endPositions {
-		pos := proto.Clone(iMsg.endPositions[idx]).(*internalpb.MsgPosition)
-		pos.ChannelName = ibNode.channelName
-		endPositions = append(endPositions, pos)
-	}
-	ibNode.replica.updateSegmentEndPosition(currentSegID, endPositions[0])
+	ibNode.replica.updateSegmentEndPosition(currentSegID, endPos)
+
 	// update segment pk filter
 	ibNode.replica.updateSegmentPKRange(currentSegID, msg.GetRowIDs())
 	return nil
diff --git a/internal/datanode/flow_graph_insert_buffer_node_test.go b/internal/datanode/flow_graph_insert_buffer_node_test.go
index 48a9a9c9f8..e900d6849b 100644
--- a/internal/datanode/flow_graph_insert_buffer_node_test.go
+++ b/internal/datanode/flow_graph_insert_buffer_node_test.go
@@ -692,20 +692,20 @@ func TestInsertBufferNode_bufferInsertMsg(t *testing.T) {
 	inMsg := genInsertMsg(insertChannelName)
 	for _, msg := range inMsg.insertMessages {
 		msg.EndTimestamp = 101 // ts valid
-		err = iBNode.bufferInsertMsg(&inMsg, msg)
+		err = iBNode.bufferInsertMsg(msg, &internalpb.MsgPosition{})
 		assert.Nil(t, err)
 	}
 
 	for _, msg := range inMsg.insertMessages {
 		msg.EndTimestamp = 99 // ts invalid
-		err = iBNode.bufferInsertMsg(&inMsg, msg)
+		err = iBNode.bufferInsertMsg(msg, &internalpb.MsgPosition{})
 		assert.NotNil(t, err)
 	}
 
 	for _, msg := range inMsg.insertMessages {
 		msg.EndTimestamp = 101 // ts valid
 		msg.RowIDs = []int64{} //misaligned data
-		err = iBNode.bufferInsertMsg(&inMsg, msg)
+		err = iBNode.bufferInsertMsg(msg, &internalpb.MsgPosition{})
 		assert.NotNil(t, err)
 	}
 }
@@ -743,3 +743,39 @@ func TestInsertBufferNode_updateSegStatesInReplica(te *testing.T) {
 	}
 
 }
+
+func TestInsertBufferNode_BufferData(te *testing.T) {
+	Params.FlushInsertBufferSize = 16
+
+	tests := []struct {
+		isValid bool
+
+		indim         int64
+		expectedLimit int64
+
+		description string
+	}{
+		{true, 1, 4194304, "Smallest of the DIM"},
+		{true, 128, 32768, "Normal DIM"},
+		{true, 32768, 128, "Largest DIM"},
+		{false, 0, 0, "Illegal DIM"},
+	}
+
+	for _, test := range tests {
+		te.Run(test.description, func(t *testing.T) {
+			idata, err := newBufferData(test.indim)
+
+			if test.isValid {
+				assert.NoError(t, err)
+				assert.NotNil(t, idata)
+
+				assert.Equal(t, test.expectedLimit, idata.limit)
+				assert.Zero(t, idata.size)
+			} else {
+				assert.Error(t, err)
+				assert.Nil(t, idata)
+			}
+		})
+
+	}
+}