diff --git a/go-api/schemapb/schema.pb.go b/go-api/schemapb/schema.pb.go
index d3d868c..d1b9f4e 100644
--- a/go-api/schemapb/schema.pb.go
+++ b/go-api/schemapb/schema.pb.go
@@ -1040,11 +1040,10 @@ func (*ScalarField) XXX_OneofWrappers() []interface{} {
 }
 
 type SparseFloatRow struct {
-	// dim is the max dimension of the current vector
-	Dim int32 `protobuf:"varint,1,opt,name=dim,proto3" json:"dim,omitempty"`
-	// len(indices) == len(values), indices must be sorted
-	Indices              *IntArray   `protobuf:"bytes,2,opt,name=indices,proto3" json:"indices,omitempty"`
-	Values               *FloatArray `protobuf:"bytes,3,opt,name=values,proto3" json:"values,omitempty"`
+	// len(indices) == len(values)
+	// data in indices and values must be sorted by the index
+	Indices              *IntArray   `protobuf:"bytes,1,opt,name=indices,proto3" json:"indices,omitempty"`
+	Values               *FloatArray `protobuf:"bytes,2,opt,name=values,proto3" json:"values,omitempty"`
 	XXX_NoUnkeyedLiteral struct{}    `json:"-"`
 	XXX_unrecognized     []byte      `json:"-"`
 	XXX_sizecache        int32       `json:"-"`
@@ -1075,13 +1074,6 @@ func (m *SparseFloatRow) XXX_DiscardUnknown() {
 
 var xxx_messageInfo_SparseFloatRow proto.InternalMessageInfo
 
-func (m *SparseFloatRow) GetDim() int32 {
-	if m != nil {
-		return m.Dim
-	}
-	return 0
-}
-
 func (m *SparseFloatRow) GetIndices() *IntArray {
 	if m != nil {
 		return m.Indices
@@ -1098,12 +1090,12 @@ func (m *SparseFloatRow) GetValues() *FloatArray {
 
 // beta, api may change
 type SparseFloatArray struct {
+	Contents []*SparseFloatRow `protobuf:"bytes,1,rep,name=contents,proto3" json:"contents,omitempty"`
 	// dim is the max dimension of the current batch of vectors
-	Dim                  int32             `protobuf:"varint,1,opt,name=dim,proto3" json:"dim,omitempty"`
-	Contents             []*SparseFloatRow `protobuf:"bytes,2,rep,name=contents,proto3" json:"contents,omitempty"`
-	XXX_NoUnkeyedLiteral struct{}          `json:"-"`
-	XXX_unrecognized     []byte            `json:"-"`
-	XXX_sizecache        int32             `json:"-"`
+	Dim                  int64    `protobuf:"varint,2,opt,name=dim,proto3" json:"dim,omitempty"`
+	XXX_NoUnkeyedLiteral struct{} `json:"-"`
+	XXX_unrecognized     []byte   `json:"-"`
+	XXX_sizecache        int32    `json:"-"`
 }
 
 func (m *SparseFloatArray) Reset()         { *m = SparseFloatArray{} }
@@ -1131,18 +1123,18 @@ func (m *SparseFloatArray) XXX_DiscardUnknown() {
 
 var xxx_messageInfo_SparseFloatArray proto.InternalMessageInfo
 
-func (m *SparseFloatArray) GetDim() int32 {
+func (m *SparseFloatArray) GetContents() []*SparseFloatRow {
 	if m != nil {
-		return m.Dim
+		return m.Contents
 	}
-	return 0
+	return nil
 }
 
-func (m *SparseFloatArray) GetContents() []*SparseFloatRow {
+func (m *SparseFloatArray) GetDim() int64 {
 	if m != nil {
-		return m.Contents
+		return m.Dim
 	}
-	return nil
+	return 0
 }
 
 type VectorField struct {
@@ -1737,108 +1729,108 @@ func init() {
 func init() { proto.RegisterFile("schema.proto", fileDescriptor_1c5fb4d8cc22d66a) }
 
 var fileDescriptor_1c5fb4d8cc22d66a = []byte{
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+	0x00, 0x00,
 }
diff --git a/proto/schema.proto b/proto/schema.proto
index b80ba80..bcd0ab1 100644
--- a/proto/schema.proto
+++ b/proto/schema.proto
@@ -126,18 +126,17 @@ message ScalarField {
 }
 
 message SparseFloatRow {
-  // dim is the max dimension of the current vector
-  int32 dim = 1;
-  // len(indices) == len(values), indices must be sorted
-  IntArray indices = 2;
-  FloatArray values = 3;
+  // len(indices) == len(values)
+  // data in indices and values must be sorted by the index
+  IntArray indices = 1;
+  FloatArray values = 2;
 }
 
 // beta, api may change
 message SparseFloatArray {
+  repeated SparseFloatRow contents = 1;
   // dim is the max dimension of the current batch of vectors
-  int32 dim = 1;
-  repeated SparseFloatRow contents = 2;
+  int64 dim = 2;
 }
 
 message VectorField {