diff --git a/executor.go b/executor.go
index 34eca4026..03d18f936 100644
--- a/executor.go
+++ b/executor.go
@@ -375,7 +375,7 @@ func (e *executor) executeBitmapCall(ctx context.Context, index string, c *pql.C
 	}
 
 	if opt.ExcludeColumns {
-		row.segments = []RowSegment{}
+		row.segments = []rowSegment{}
 	}
 
 	return row, nil
diff --git a/fragment.go b/fragment.go
index dc7ded5b8..8c5fbf787 100644
--- a/fragment.go
+++ b/fragment.go
@@ -343,7 +343,7 @@ func (f *fragment) unprotectedRow(rowID uint64, checkRowCache bool, updateRowCac
 	// We Clone() data because otherwise row will contains pointers to containers in storage.
 	// This causes unexpected results when we cache the row and try to use it later.
 	row := &Row{
-		segments: []RowSegment{{
+		segments: []rowSegment{{
 			data:     *data.Clone(),
 			shard:    f.shard,
 			writable: false,
diff --git a/row.go b/row.go
index 109dbc296..38ba24f9b 100644
--- a/row.go
+++ b/row.go
@@ -24,7 +24,7 @@ import (
 // Row is a set of integers (the associated columns), and attributes which are
 // arbitrary key/value pairs storing metadata about what the row represents.
 type Row struct {
-	segments []RowSegment
+	segments []rowSegment
 
 	// String keys translated to/from segment columns.
 	Keys []string
@@ -44,7 +44,7 @@ func NewRow(columns ...uint64) *Row {
 
 // Merge merges data from other into r.
 func (r *Row) Merge(other *Row) {
-	var segments []RowSegment
+	var segments []rowSegment
 
 	itr := newMergeSegmentIterator(r.segments, other.segments)
 	for s0, s1 := itr.next(); s0 != nil || s1 != nil; s0, s1 = itr.next() {
@@ -84,7 +84,7 @@ func (r *Row) intersectionCount(other *Row) uint64 {
 
 // intersect returns the itersection of r and other.
 func (r *Row) intersect(other *Row) *Row {
-	var segments []RowSegment
+	var segments []rowSegment
 
 	itr := newMergeSegmentIterator(r.segments, other.segments)
 	for s0, s1 := itr.next(); s0 != nil || s1 != nil; s0, s1 = itr.next() {
@@ -100,7 +100,7 @@ func (r *Row) intersect(other *Row) *Row {
 
 // Xor returns the xor of r and other.
 func (r *Row) Xor(other *Row) *Row {
-	var segments []RowSegment
+	var segments []rowSegment
 
 	itr := newMergeSegmentIterator(r.segments, other.segments)
 	for s0, s1 := itr.next(); s0 != nil || s1 != nil; s0, s1 = itr.next() {
@@ -120,7 +120,7 @@ func (r *Row) Xor(other *Row) *Row {
 
 // Union returns the bitwise union of r and other.
 func (r *Row) Union(other *Row) *Row {
-	var segments []RowSegment
+	var segments []rowSegment
 	itr := newMergeSegmentIterator(r.segments, other.segments)
 	for s0, s1 := itr.next(); s0 != nil || s1 != nil; s0, s1 = itr.next() {
 		if s1 == nil {
@@ -138,7 +138,7 @@ func (r *Row) Union(other *Row) *Row {
 
 // Difference returns the diff of r and other.
 func (r *Row) Difference(other *Row) *Row {
-	var segments []RowSegment
+	var segments []rowSegment
 
 	itr := newMergeSegmentIterator(r.segments, other.segments)
 	for s0, s1 := itr.next(); s0 != nil || s1 != nil; s0, s1 = itr.next() {
@@ -169,13 +169,13 @@ func (r *Row) clearBit(i uint64) (changed bool) {
 }
 
 // Segments returns a list of all segments in the row.
-func (r *Row) Segments() []RowSegment {
+func (r *Row) Segments() []rowSegment {
 	return r.segments
 }
 
 // segment returns a segment for a given shard.
 // Returns nil if segment does not exist.
-func (r *Row) segment(shard uint64) *RowSegment {
+func (r *Row) segment(shard uint64) *rowSegment {
 	if i := sort.Search(len(r.segments), func(i int) bool {
 		return r.segments[i].shard >= shard
 	}); i < len(r.segments) && r.segments[i].shard == shard {
@@ -184,7 +184,7 @@ func (r *Row) segment(shard uint64) *RowSegment {
 	return nil
 }
 
-func (r *Row) createSegmentIfNotExists(shard uint64) *RowSegment {
+func (r *Row) createSegmentIfNotExists(shard uint64) *rowSegment {
 	i := sort.Search(len(r.segments), func(i int) bool {
 		return r.segments[i].shard >= shard
 	})
@@ -195,11 +195,11 @@ func (r *Row) createSegmentIfNotExists(shard uint64) *RowSegment {
 	}
 
 	// Insert new segment.
-	r.segments = append(r.segments, RowSegment{data: *roaring.NewBitmap()})
+	r.segments = append(r.segments, rowSegment{data: *roaring.NewBitmap()})
 	if i < len(r.segments) {
 		copy(r.segments[i+1:], r.segments[i:])
 	}
-	r.segments[i] = RowSegment{
+	r.segments[i] = rowSegment{
 		data:     *roaring.NewBitmap(),
 		shard:    shard,
 		writable: true,
@@ -251,10 +251,10 @@ func (r *Row) Columns() []uint64 {
 	return a
 }
 
-// RowSegment holds a subset of a row.
+// rowSegment holds a subset of a row.
 // This could point to a mmapped roaring bitmap or an in-memory bitmap. The
 // width of the segment will always match the shard width.
-type RowSegment struct {
+type rowSegment struct {
 	// Shard this segment belongs to
 	shard uint64
 
@@ -270,7 +270,7 @@ type RowSegment struct {
 
 // Merge adds chunks from other to s.
 // Chunks in s are overwritten if they exist in other.
-func (s *RowSegment) Merge(other *RowSegment) {
+func (s *rowSegment) Merge(other *rowSegment) {
 	s.ensureWritable()
 
 	itr := other.data.Iterator()
@@ -280,15 +280,15 @@ func (s *RowSegment) Merge(other *RowSegment) {
 }
 
 // IntersectionCount returns the number of intersections between s and other.
-func (s *RowSegment) IntersectionCount(other *RowSegment) uint64 {
+func (s *rowSegment) IntersectionCount(other *rowSegment) uint64 {
 	return s.data.IntersectionCount(&other.data)
 }
 
 // Intersect returns the itersection of s and other.
-func (s *RowSegment) Intersect(other *RowSegment) *RowSegment {
+func (s *rowSegment) Intersect(other *rowSegment) *rowSegment {
 	data := s.data.Intersect(&other.data)
 
-	return &RowSegment{
+	return &rowSegment{
 		data:  *data,
 		shard: s.shard,
 		n:     data.Count(),
@@ -296,10 +296,10 @@ func (s *RowSegment) Intersect(other *RowSegment) *RowSegment {
 }
 
 // Union returns the bitwise union of s and other.
-func (s *RowSegment) Union(other *RowSegment) *RowSegment {
+func (s *rowSegment) Union(other *rowSegment) *rowSegment {
 	data := s.data.Union(&other.data)
 
-	return &RowSegment{
+	return &rowSegment{
 		data:  *data,
 		shard: s.shard,
 		n:     data.Count(),
@@ -307,10 +307,10 @@ func (s *RowSegment) Union(other *RowSegment) *RowSegment {
 }
 
 // Difference returns the diff of s and other.
-func (s *RowSegment) Difference(other *RowSegment) *RowSegment {
+func (s *rowSegment) Difference(other *rowSegment) *rowSegment {
 	data := s.data.Difference(&other.data)
 
-	return &RowSegment{
+	return &rowSegment{
 		data:  *data,
 		shard: s.shard,
 		n:     data.Count(),
@@ -318,10 +318,10 @@ func (s *RowSegment) Difference(other *RowSegment) *RowSegment {
 }
 
 // Xor returns the xor of s and other.
-func (s *RowSegment) Xor(other *RowSegment) *RowSegment {
+func (s *rowSegment) Xor(other *rowSegment) *rowSegment {
 	data := s.data.Xor(&other.data)
 
-	return &RowSegment{
+	return &rowSegment{
 		data:  *data,
 		shard: s.shard,
 		n:     data.Count(),
@@ -329,7 +329,7 @@ func (s *RowSegment) Xor(other *RowSegment) *RowSegment {
 }
 
 // SetBit sets the i-th column of the row.
-func (s *RowSegment) SetBit(i uint64) (changed bool) {
+func (s *rowSegment) SetBit(i uint64) (changed bool) {
 	s.ensureWritable()
 	changed, _ = s.data.Add(i)
 	if changed {
@@ -339,7 +339,7 @@ func (s *RowSegment) SetBit(i uint64) (changed bool) {
 }
 
 // ClearBit clears the i-th column of the row.
-func (s *RowSegment) ClearBit(i uint64) (changed bool) {
+func (s *rowSegment) ClearBit(i uint64) (changed bool) {
 	s.ensureWritable()
 
 	changed, _ = s.data.Remove(i)
@@ -350,12 +350,12 @@ func (s *RowSegment) ClearBit(i uint64) (changed bool) {
 }
 
 // InvalidateCount updates the cached count in the row.
-func (s *RowSegment) InvalidateCount() {
+func (s *rowSegment) InvalidateCount() {
 	s.n = s.data.Count()
 }
 
 // Columns returns a list of all columns set in the segment.
-func (s *RowSegment) Columns() []uint64 {
+func (s *rowSegment) Columns() []uint64 {
 	a := make([]uint64, 0, s.Count())
 	itr := s.data.Iterator()
 	for v, eof := itr.Next(); !eof; v, eof = itr.Next() {
@@ -365,10 +365,10 @@ func (s *RowSegment) Columns() []uint64 {
 }
 
 // Count returns the number of set columns in the row.
-func (s *RowSegment) Count() uint64 { return s.n }
+func (s *rowSegment) Count() uint64 { return s.n }
 
 // ensureWritable clones the segment if it is pointing to non-writable data.
-func (s *RowSegment) ensureWritable() {
+func (s *rowSegment) ensureWritable() {
 	if s.writable {
 		return
 	}
@@ -379,16 +379,16 @@ func (s *RowSegment) ensureWritable() {
 
 // mergeSegmentIterator produces an iterator that loops through two sets of segments.
 type mergeSegmentIterator struct {
-	a0, a1 []RowSegment
+	a0, a1 []rowSegment
 }
 
 // newMergeSegmentIterator returns a new instance of mergeSegmentIterator.
-func newMergeSegmentIterator(a0, a1 []RowSegment) mergeSegmentIterator {
+func newMergeSegmentIterator(a0, a1 []rowSegment) mergeSegmentIterator {
 	return mergeSegmentIterator{a0: a0, a1: a1}
 }
 
 // next returns the next set of segments.
-func (itr *mergeSegmentIterator) next() (s0, s1 *RowSegment) {
+func (itr *mergeSegmentIterator) next() (s0, s1 *rowSegment) {
 	// Find current segments.
 	if len(itr.a0) > 0 {
 		s0 = &itr.a0[0]