diff --git a/src/dbnode/persist/fs/commitlog/commit_log.go b/src/dbnode/persist/fs/commitlog/commit_log.go
index 12c338aee0..e49a81bdef 100644
--- a/src/dbnode/persist/fs/commitlog/commit_log.go
+++ b/src/dbnode/persist/fs/commitlog/commit_log.go
@@ -445,7 +445,7 @@ func (l *commitLog) write() {
 		}
 
 		numWritesSuccess := int64(0)
-		if write.write.writeBatch.Writes == nil {
+		if write.write.writeBatch == nil {
 			// Handle individual write case
 			write := write.write.write
 			err := l.writerState.writer.Write(write.Series,
@@ -457,8 +457,9 @@ func (l *commitLog) write() {
 			numWritesSuccess++
 		} else {
 			// Handle write batch case
-			for i := 0; i < len(write.write.writeBatch.Writes); i++ {
-				write := write.write.writeBatch.Writes[i]
+			iter := write.write.writeBatch.Iter()
+			for iter.Next() {
+				write := iter.Current().Write
 				err := l.writerState.writer.Write(write.Series,
 					write.Datapoint, write.Unit, write.Annotation)
 				if err != nil {
diff --git a/src/dbnode/storage/database.go b/src/dbnode/storage/database.go
index a57e9d118d..df162f2be9 100644
--- a/src/dbnode/storage/database.go
+++ b/src/dbnode/storage/database.go
@@ -531,6 +531,21 @@ func (d *db) WriteTagged(
 	return d.commitLog.Write(ctx, series, dp, unit, annotation)
 }
 
+func (d *db) WriteTaggedBatchWriter(namespace ident.ID, batchSize int) (ts.BatchWriter, error) {
+	n, err := d.namespaceFor(namespace)
+	if err != nil {
+		// TODO: Fix metric
+		d.metrics.unknownNamespaceWriteTagged.Inc(1)
+		return nil, err
+	}
+
+	var (
+		nsID        = n.ID()
+		batchWriter = ts.NewWriteBatch(batchSize, 100000, nsID, d.shardSet.Lookup)
+	)
+	return batchWriter, nil
+}
+
 func (d *db) WriteTaggedBatch(
 	ctx context.Context,
 	namespace ident.ID,
@@ -542,15 +557,18 @@ func (d *db) WriteTaggedBatch(
 		return err
 	}
 
-	for i, write := range writes {
+	iter := writes.Iter()
+	for iter.Next() {
+		write := iter.Current()
+
 		series, err := n.WriteTagged(
 			ctx,
-			write.Series.ID,
-			write.Series.TagIter,
-			write.Datapoint.Timestamp,
-			write.Datapoint.Value,
-			write.Unit,
-			write.Annotation,
+			write.Write.Series.ID,
+			write.TagIter,
+			write.Write.Datapoint.Timestamp,
+			write.Write.Datapoint.Value,
+			write.Write.Unit,
+			write.Write.Annotation,
 		)
 		if err == commitlog.ErrCommitLogQueueFull {
 			d.errors.Record(1)
@@ -558,7 +576,7 @@ func (d *db) WriteTaggedBatch(
 		if err != nil {
 			return err
 		}
-		writes[i].Series = series
+		iter.UpdateSeries(series)
 	}
 
 	return d.commitLog.WriteBatch(ctx, writes)
diff --git a/src/dbnode/storage/namespace_test.go b/src/dbnode/storage/namespace_test.go
index fa0a806790..93d02b5b5d 100644
--- a/src/dbnode/storage/namespace_test.go
+++ b/src/dbnode/storage/namespace_test.go
@@ -37,6 +37,7 @@ import (
 	"github.com/m3db/m3/src/dbnode/storage/index"
 	"github.com/m3db/m3/src/dbnode/storage/namespace"
 	"github.com/m3db/m3/src/dbnode/storage/repair"
+	"github.com/m3db/m3/src/dbnode/ts"
 	"github.com/m3db/m3/src/dbnode/x/metrics"
 	"github.com/m3db/m3x/context"
 	xerrors "github.com/m3db/m3x/errors"
@@ -154,7 +155,7 @@ func TestNamespaceWriteShardOwned(t *testing.T) {
 	defer ctx.Close()
 
 	id := ident.StringID("foo")
-	ts := time.Now()
+	now := time.Now()
 	val := 0.0
 	unit := xtime.Second
 	ant := []byte(nil)
@@ -162,10 +163,10 @@ func TestNamespaceWriteShardOwned(t *testing.T) {
 	ns, closer := newTestNamespace(t)
 	defer closer()
 	shard := NewMockdatabaseShard(ctrl)
-	shard.EXPECT().Write(ctx, id, ts, val, unit, ant).Return(ts.Series{}, nil)
+	shard.EXPECT().Write(ctx, id, now, val, unit, ant).Return(ts.Series{}, nil)
 	ns.shards[testShardIDs[0].ID()] = shard
 
-	_, err := ns.Write(ctx, id, ts, val, unit, ant)
+	_, err := ns.Write(ctx, id, now, val, unit, ant)
 	require.NoError(t, err)
 }
 
@@ -1024,15 +1025,15 @@ func TestNamespaceIndexInsert(t *testing.T) {
 	defer closer()
 
 	ctx := context.NewContext()
-	ts := time.Now()
+	now := time.Now()
 
 	shard := NewMockdatabaseShard(ctrl)
 	shard.EXPECT().WriteTagged(ctx, ident.NewIDMatcher("a"), ident.EmptyTagIterator,
-		ts, 1.0, xtime.Second, nil).Return(ts.Series{}, nil)
+		now, 1.0, xtime.Second, nil).Return(ts.Series{}, nil)
 	ns.shards[testShardIDs[0].ID()] = shard
 
 	_, err := ns.WriteTagged(ctx, ident.StringID("a"),
-		ident.EmptyTagIterator, ts, 1.0, xtime.Second, nil)
+		ident.EmptyTagIterator, now, 1.0, xtime.Second, nil)
 	require.NoError(t, err)
 
 	shard.EXPECT().Close()
diff --git a/src/dbnode/ts/types.go b/src/dbnode/ts/types.go
index 7601bc4ccd..6a5b423139 100644
--- a/src/dbnode/ts/types.go
+++ b/src/dbnode/ts/types.go
@@ -49,8 +49,6 @@ type Series struct {
 	// Tags are the series tags
 	Tags ident.Tags
 
-	TagIter ident.TagIterator
-
 	// Shard is the shard the series belongs to
 	Shard uint32
 }