diff --git a/api.go b/api.go
index 9e6ee1daa..c8aa2b5cc 100644
--- a/api.go
+++ b/api.go
@@ -686,6 +686,12 @@ func (api *API) Import(_ context.Context, req *ImportRequest) error {
 		timestamps[i] = &t
 	}
 
+	// Import columnIDs into existence field.
+	if err := importExistenceColumns(index, req.ColumnIDs); err != nil {
+		api.server.logger.Printf("import existence error: index=%s, field=%s, shard=%d, columns=%d, err=%s", req.Index, req.Field, req.Shard, len(req.ColumnIDs), err)
+		return errors.Wrap(err, "importing existence columns")
+	}
+
 	// Import into fragment.
 	err = field.Import(req.RowIDs, req.ColumnIDs, timestamps)
 	if err != nil {
@@ -720,6 +726,12 @@ func (api *API) ImportValue(_ context.Context, req *ImportValueRequest) error {
 		}
 	}
 
+	// Import columnIDs into existence field.
+	if err := importExistenceColumns(index, req.ColumnIDs); err != nil {
+		api.server.logger.Printf("import existence error: index=%s, field=%s, shard=%d, columns=%d, err=%s", req.Index, req.Field, req.Shard, len(req.ColumnIDs), err)
+		return errors.Wrap(err, "importing existence columns")
+	}
+
 	// Import into fragment.
 	err = field.importValue(req.ColumnIDs, req.Values)
 	if err != nil {
@@ -728,6 +740,16 @@ func (api *API) ImportValue(_ context.Context, req *ImportValueRequest) error {
 	return errors.Wrap(err, "importing")
 }
 
+func importExistenceColumns(index *Index, columnIDs []uint64) error {
+	ef := index.existenceField()
+	if ef == nil {
+		return nil
+	}
+
+	existenceRowIDs := make([]uint64, len(columnIDs))
+	return ef.Import(existenceRowIDs, columnIDs, nil)
+}
+
 // MaxShards returns the maximum shard number for each index in a map.
 func (api *API) MaxShards(_ context.Context) map[string]uint64 {
 	m := make(map[string]uint64)
diff --git a/encoding/proto/proto.go b/encoding/proto/proto.go
index a19f1e548..0fcd9df3a 100644
--- a/encoding/proto/proto.go
+++ b/encoding/proto/proto.go
@@ -509,7 +509,8 @@ func encodeCreateIndexMessage(m *pilosa.CreateIndexMessage) *internal.CreateInde
 
 func encodeIndexMeta(m *pilosa.IndexOptions) *internal.IndexMeta {
 	return &internal.IndexMeta{
-		Keys: m.Keys,
+		Keys:           m.Keys,
+		TrackExistence: m.TrackExistence,
 	}
 }
 
@@ -741,6 +742,7 @@ func decodeCreateIndexMessage(pb *internal.CreateIndexMessage, m *pilosa.CreateI
 
 func decodeIndexMeta(pb *internal.IndexMeta, m *pilosa.IndexOptions) {
 	m.Keys = pb.Keys
+	m.TrackExistence = pb.TrackExistence
 }
 
 func decodeDeleteIndexMessage(pb *internal.DeleteIndexMessage, m *pilosa.DeleteIndexMessage) {
diff --git a/executor.go b/executor.go
index 2888b9270..389cb573b 100644
--- a/executor.go
+++ b/executor.go
@@ -1131,6 +1131,13 @@ func (e *executor) executeSet(ctx context.Context, index string, c *pql.Call, op
 		return false, ErrFieldNotFound
 	}
 
+	// Set column on existence field.
+	if ef := idx.existenceField(); ef != nil {
+		if _, err := ef.SetBit(0, colID, nil); err != nil {
+			return false, errors.Wrap(err, "setting existence column")
+		}
+	}
+
 	if f.Type() == FieldTypeInt {
 		// Read remaining fields using labels.
 		rowVal, ok, err := c.IntArg(fieldName)
diff --git a/executor_test.go b/executor_test.go
index b6fa5ccfa..5704e607b 100644
--- a/executor_test.go
+++ b/executor_test.go
@@ -17,6 +17,7 @@ package pilosa_test
 import (
 	"context"
 	"fmt"
+	"math/rand"
 	"reflect"
 	"strconv"
 	"strings"
@@ -32,8 +33,8 @@ import (
 	"github.com/pkg/errors"
 )
 
-// Ensure a bitmap query can be executed.
-func TestExecutor_Execute_Bitmap(t *testing.T) {
+// Ensure a row query can be executed.
+func TestExecutor_Execute_Row(t *testing.T) {
 	t.Run("Row", func(t *testing.T) {
 		c := test.MustRunCluster(t, 1)
 		defer c.Close()
@@ -282,7 +283,7 @@ func TestExecutor_Execute_SetBit(t *testing.T) {
 		t.Run("OK", func(t *testing.T) {
 			hldr.ClearBit("i", "f", 11, 1)
 			if n := hldr.Row("i", "f", 11).Count(); n != 0 {
-				t.Fatalf("unexpected bitmap count: %d", n)
+				t.Fatalf("unexpected row count: %d", n)
 			}
 
 			if res, err := cmd.API.Query(context.Background(), &pilosa.QueryRequest{Index: "i", Query: `Set(1, f=11)`}); err != nil {
@@ -294,7 +295,7 @@ func TestExecutor_Execute_SetBit(t *testing.T) {
 			}
 
 			if n := hldr.Row("i", "f", 11).Count(); n != 1 {
-				t.Fatalf("unexpected bitmap count: %d", n)
+				t.Fatalf("unexpected row count: %d", n)
 			}
 			if res, err := cmd.API.Query(context.Background(), &pilosa.QueryRequest{Index: "i", Query: `Set(1, f=11)`}); err != nil {
 				t.Fatal(err)
@@ -327,7 +328,7 @@ func TestExecutor_Execute_SetBit(t *testing.T) {
 		t.Run("OK", func(t *testing.T) {
 			hldr.SetBit("i", "f", 1, 0)
 			if n := hldr.Row("i", "f", 11).Count(); n != 0 {
-				t.Fatalf("unexpected bitmap count: %d", n)
+				t.Fatalf("unexpected row count: %d", n)
 			}
 
 			if res, err := cmd.API.Query(context.Background(), &pilosa.QueryRequest{Index: "i", Query: `Set("foo", f=11)`}); err != nil {
@@ -339,7 +340,7 @@ func TestExecutor_Execute_SetBit(t *testing.T) {
 			}
 
 			if n := hldr.Row("i", "f", 11).Count(); n != 1 {
-				t.Fatalf("unexpected bitmap count: %d", n)
+				t.Fatalf("unexpected row count: %d", n)
 			}
 			if res, err := cmd.API.Query(context.Background(), &pilosa.QueryRequest{Index: "i", Query: `Set("foo", f=11)`}); err != nil {
 				t.Fatal(err)
@@ -476,7 +477,7 @@ func TestExecutor_Execute_SetRowAttrs(t *testing.T) {
 	}
 	t.Run("rowID", func(t *testing.T) {
 		// Set two attrs on f/10.
-		// Also set attrs on other bitmaps and fields to test isolation.
+		// Also set attrs on other rows and fields to test isolation.
 		if _, err := c[0].API.Query(context.Background(), &pilosa.QueryRequest{Index: "i", Query: `SetRowAttrs(f, 10, foo="bar")`}); err != nil {
 			t.Fatal(err)
 		}
@@ -494,13 +495,13 @@ func TestExecutor_Execute_SetRowAttrs(t *testing.T) {
 		if m, err := f.RowAttrStore().Attrs(10); err != nil {
 			t.Fatal(err)
 		} else if !reflect.DeepEqual(m, map[string]interface{}{"foo": "bar", "baz": int64(123), "bat": true}) {
-			t.Fatalf("unexpected bitmap attr: %#v", m)
+			t.Fatalf("unexpected row attr: %#v", m)
 		}
 	})
 
 	t.Run("rowKey", func(t *testing.T) {
 		// Set two attrs on f/10.
-		// Also set attrs on other bitmaps and fields to test isolation.
+		// Also set attrs on other rows and fields to test isolation.
 		if _, err := c[0].API.Query(context.Background(), &pilosa.QueryRequest{Index: "i", Query: `SetRowAttrs(kf, "row10", foo="bar")`}); err != nil {
 			t.Fatal(err)
 		}
@@ -663,7 +664,7 @@ func TestExecutor_Execute_TopN_fill_small(t *testing.T) {
 	}
 }
 
-// Ensure a TopN() query with a source bitmap can be executed.
+// Ensure a TopN() query with a source row can be executed.
 func TestExecutor_Execute_TopN_Src(t *testing.T) {
 	c := test.MustRunCluster(t, 1)
 	defer c.Close()
@@ -723,7 +724,7 @@ func TestExecutor_Execute_TopN_Attr(t *testing.T) {
 
 }
 
-//Ensure TopN handles Attribute filters with source bitmap
+//Ensure TopN handles Attribute filters with source row
 func TestExecutor_Execute_TopN_Attr_Src(t *testing.T) {
 	c := test.MustRunCluster(t, 1)
 	defer c.Close()
@@ -1495,3 +1496,87 @@ func TestExecutor_QueryCall(t *testing.T) {
 		}
 	})
 }
+
+// Ensure an existence field is maintained.
+func TestExecutor_Execute_Existence(t *testing.T) {
+	t.Run("Row", func(t *testing.T) {
+		c := test.MustRunCluster(t, 1)
+		defer c.Close()
+		hldr := test.Holder{Holder: c[0].Server.Holder()}
+		index := hldr.MustCreateIndexIfNotExists("i", pilosa.IndexOptions{TrackExistence: true})
+		_, err := index.CreateField("f", pilosa.OptFieldTypeDefault())
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		// Set bits.
+		if _, err := c[0].API.Query(context.Background(), &pilosa.QueryRequest{Index: "i", Query: `` +
+			fmt.Sprintf("Set(%d, f=%d)\n", 3, 10) +
+			fmt.Sprintf("Set(%d, f=%d)\n", ShardWidth+1, 10) +
+			fmt.Sprintf("Set(%d, f=%d)\n", ShardWidth+2, 20),
+		}); err != nil {
+			t.Fatal(err)
+		}
+
+		if res, err := c[0].API.Query(context.Background(), &pilosa.QueryRequest{Index: "i", Query: `Row(f=10)`}); err != nil {
+			t.Fatal(err)
+		} else if bits := res.Results[0].(*pilosa.Row).Columns(); !reflect.DeepEqual(bits, []uint64{3, ShardWidth + 1}) {
+			t.Fatalf("unexpected columns: %+v", bits)
+		}
+
+		if res, err := c[0].API.Query(context.Background(), &pilosa.QueryRequest{Index: "i", Query: `Row(exists=0)`}); err != nil {
+			t.Fatal(err)
+		} else if bits := res.Results[0].(*pilosa.Row).Columns(); !reflect.DeepEqual(bits, []uint64{3, ShardWidth + 1, ShardWidth + 2}) {
+			t.Fatalf("unexpected existence columns: %+v", bits)
+		}
+
+		// Reopen cluster to ensure existence field is reloaded.
+		if err := c[0].Reopen(); err != nil {
+			t.Fatal(err)
+		}
+
+		if res, err := c[0].API.Query(context.Background(), &pilosa.QueryRequest{Index: "i", Query: `Row(exists=0)`}); err != nil {
+			t.Fatal(err)
+		} else if bits := res.Results[0].(*pilosa.Row).Columns(); !reflect.DeepEqual(bits, []uint64{3, ShardWidth + 1, ShardWidth + 2}) {
+			t.Fatalf("unexpected existence columns after reopen: %+v", bits)
+		}
+	})
+}
+
+func benchmarkExistence(nn bool, b *testing.B) {
+	c := test.MustRunCluster(b, 1)
+	defer c.Close()
+	hldr := test.Holder{Holder: c[0].Server.Holder()}
+
+	indexName := "i"
+	fieldName := "f"
+
+	index := hldr.MustCreateIndexIfNotExists(indexName, pilosa.IndexOptions{TrackExistence: nn})
+	// Create field.
+	if _, err := index.CreateFieldIfNotExists(fieldName); err != nil {
+		b.Fatal(err)
+	}
+
+	bitCount := 10000
+	req := &pilosa.ImportRequest{
+		Index:     indexName,
+		Field:     fieldName,
+		Shard:     0,
+		RowIDs:    make([]uint64, bitCount),
+		ColumnIDs: make([]uint64, bitCount),
+	}
+	for i := 0; i < bitCount; i++ {
+		req.RowIDs[i] = uint64(rand.Intn(100000))
+		req.ColumnIDs[i] = uint64(rand.Intn(1 << 20))
+	}
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		if err := c[0].API.Import(context.Background(), req); err != nil {
+			b.Fatal(err)
+		}
+	}
+}
+
+func BenchmarkExecutor_Existence_True(b *testing.B)  { benchmarkExistence(true, b) }
+func BenchmarkExecutor_Existence_False(b *testing.B) { benchmarkExistence(false, b) }
diff --git a/field.go b/field.go
index 9fb352fc1..7a60f3b3f 100644
--- a/field.go
+++ b/field.go
@@ -159,12 +159,17 @@ func OptFieldTypeMutex(cacheType string, cacheSize uint32) FieldOption {
 func NewField(path, index, name string, opts FieldOption) (*Field, error) {
 	err := validateName(name)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "validating name")
 	}
 
+	return newField(path, index, name, opts)
+}
+
+// newField returns a new instance of field (without name validation).
+func newField(path, index, name string, opts FieldOption) (*Field, error) {
 	// Apply functional option.
 	fo := FieldOptions{}
-	err = opts(&fo)
+	err := opts(&fo)
 	if err != nil {
 		return nil, errors.Wrap(err, "applying option")
 	}
diff --git a/fragment_internal_test.go b/fragment_internal_test.go
index c85b7e88c..a0d1354ba 100644
--- a/fragment_internal_test.go
+++ b/fragment_internal_test.go
@@ -746,7 +746,7 @@ func TestFragment_TopN_CacheSize(t *testing.T) {
 	cacheSize := uint32(3)
 
 	// Create Index.
-	index := mustOpenIndex()
+	index := mustOpenIndex(IndexOptions{})
 	defer index.Close()
 
 	// Create field.
@@ -912,7 +912,7 @@ func TestFragment_LRUCache_Persistence(t *testing.T) {
 
 // Ensure a fragment's cache can be persisted between restarts.
 func TestFragment_RankCache_Persistence(t *testing.T) {
-	index := mustOpenIndex()
+	index := mustOpenIndex(IndexOptions{})
 	defer index.Close()
 
 	// Create field.
diff --git a/holder.go b/holder.go
index 957765511..794104e53 100644
--- a/holder.go
+++ b/holder.go
@@ -38,6 +38,9 @@ const (
 
 	// fileLimit is the maximum open file limit (ulimit -n) to automatically set.
 	fileLimit = 262144 // (512^2)
+
+	// existenceFieldName is the name of the internal field used to store existence values.
+	existenceFieldName = "exists"
 )
 
 // Holder represents a container for indexes.
@@ -354,6 +357,7 @@ func (h *Holder) createIndex(name string, opt IndexOptions) (*Index, error) {
 	}
 
 	index.keys = opt.Keys
+	index.trackExistence = opt.TrackExistence
 
 	if err := index.Open(); err != nil {
 		return nil, errors.Wrap(err, "opening")
diff --git a/http/client_test.go b/http/client_test.go
index 131161d3c..f0e8cf132 100644
--- a/http/client_test.go
+++ b/http/client_test.go
@@ -196,7 +196,7 @@ func TestClient_Export(t *testing.T) {
 		{RowID: 2, ColumnID: 203, RowKey: "row2", ColumnKey: "col203"},
 	}
 
-	t.Run("Import unkeyed,unkeyedf", func(t *testing.T) {
+	t.Run("Export unkeyed,unkeyedf", func(t *testing.T) {
 		// Populate data.
 		for _, bit := range data {
 			_, err := c.Query(context.Background(), "unkeyed", &pilosa.QueryRequest{
@@ -230,7 +230,7 @@ func TestClient_Export(t *testing.T) {
 		}
 	})
 
-	t.Run("Import unkeyed,keyedf", func(t *testing.T) {
+	t.Run("Export unkeyed,keyedf", func(t *testing.T) {
 		// Populate data.
 		for _, bit := range data {
 			_, err := c.Query(context.Background(), "unkeyed", &pilosa.QueryRequest{
@@ -264,7 +264,7 @@ func TestClient_Export(t *testing.T) {
 		}
 	})
 
-	t.Run("Import keyed,unkeyedf", func(t *testing.T) {
+	t.Run("Export keyed,unkeyedf", func(t *testing.T) {
 		// Populate data.
 		for _, bit := range data {
 			_, err := c.Query(context.Background(), "keyed", &pilosa.QueryRequest{
@@ -298,7 +298,7 @@ func TestClient_Export(t *testing.T) {
 		}
 	})
 
-	t.Run("Import keyed,keyedf", func(t *testing.T) {
+	t.Run("Export keyed,keyedf", func(t *testing.T) {
 		// Populate data.
 		for _, bit := range data {
 			_, err := c.Query(context.Background(), "keyed", &pilosa.QueryRequest{
@@ -655,6 +655,83 @@ func TestClient_ImportValue(t *testing.T) {
 	}
 }
 
+// Ensure client can bulk import data while tracking existence.
+func TestClient_ImportExistence(t *testing.T) {
+	cmd := test.MustRunCluster(t, 1)[0]
+	host := cmd.URL()
+	holder := cmd.Server.Holder()
+	hldr := test.Holder{Holder: holder}
+
+	t.Run("Set", func(t *testing.T) {
+		idxName := "iset"
+		fldName := "fset"
+
+		index := hldr.MustCreateIndexIfNotExists(idxName, pilosa.IndexOptions{TrackExistence: true})
+		_, err := index.CreateFieldIfNotExists(fldName)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		// Send import request.
+		c := MustNewClient(host, http.GetHTTPClient(nil))
+		if err := c.Import(context.Background(), idxName, fldName, 0, []pilosa.Bit{
+			{RowID: 0, ColumnID: 1},
+			{RowID: 0, ColumnID: 5},
+			{RowID: 200, ColumnID: 6},
+		}); err != nil {
+			t.Fatal(err)
+		}
+
+		// Verify data.
+		if a := hldr.Row(idxName, fldName, 0).Columns(); !reflect.DeepEqual(a, []uint64{1, 5}) {
+			t.Fatalf("unexpected columns: %+v", a)
+		}
+		if a := hldr.Row(idxName, fldName, 200).Columns(); !reflect.DeepEqual(a, []uint64{6}) {
+			t.Fatalf("unexpected columns: %+v", a)
+		}
+
+		// Verify existence.
+		if a := hldr.ReadRow(idxName, "exists", 0).Columns(); !reflect.DeepEqual(a, []uint64{1, 5, 6}) {
+			t.Fatalf("unexpected existence columns: %+v", a)
+		}
+	})
+
+	t.Run("Int", func(t *testing.T) {
+		idxName := "iint"
+		fldName := "fint"
+
+		index := hldr.MustCreateIndexIfNotExists(idxName, pilosa.IndexOptions{TrackExistence: true})
+		field, err := index.CreateFieldIfNotExists(fldName, pilosa.OptFieldTypeInt(-100, 100))
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		// Send import request.
+		c := MustNewClient(host, http.GetHTTPClient(nil))
+		if err := c.ImportValue(context.Background(), idxName, fldName, 0, []pilosa.FieldValue{
+			{ColumnID: 1, Value: -10},
+			{ColumnID: 2, Value: 20},
+			{ColumnID: 3, Value: 40},
+		}); err != nil {
+			t.Fatal(err)
+		}
+
+		// Verify Sum.
+		sum, cnt, err := field.Sum(nil, fldName)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if sum != 50 || cnt != 3 {
+			t.Fatalf("unexpected values: got sum=%v, count=%v; expected sum=50, cnt=3", sum, cnt)
+		}
+
+		// Verify existence.
+		if a := hldr.ReadRow(idxName, "exists", 0).Columns(); !reflect.DeepEqual(a, []uint64{1, 2, 3}) {
+			t.Fatalf("unexpected existence columns: %+v", a)
+		}
+	})
+}
+
 // Ensure client can retrieve a list of all checksums for blocks in a fragment.
 func TestClient_FragmentBlocks(t *testing.T) {
 	cmd := test.MustRunCluster(t, 1)[0]
diff --git a/index.go b/index.go
index 0547d07d2..0992ab213 100644
--- a/index.go
+++ b/index.go
@@ -36,6 +36,10 @@ type Index struct {
 	name string
 	keys bool // use string keys
 
+	// Existence tracking.
+	trackExistence bool
+	existenceFld   *Field
+
 	// Fields by name.
 	fields map[string]*Field
 
@@ -91,7 +95,10 @@ func (i *Index) Options() IndexOptions {
 }
 
 func (i *Index) options() IndexOptions {
-	return IndexOptions{Keys: i.keys}
+	return IndexOptions{
+		Keys:           i.keys,
+		TrackExistence: i.trackExistence,
+	}
 }
 
 // Open opens and initializes the index.
@@ -110,6 +117,12 @@ func (i *Index) Open() error {
 		return errors.Wrap(err, "opening fields")
 	}
 
+	if i.trackExistence {
+		if err := i.openExistenceField(); err != nil {
+			return errors.Wrap(err, "opening existence field")
+		}
+	}
+
 	if err := i.columnAttrs.Open(); err != nil {
 		return errors.Wrap(err, "opening attrstore")
 	}
@@ -147,6 +160,16 @@ func (i *Index) openFields() error {
 	return nil
 }
 
+// openExistenceField gets or creates the existence field and associates it to the index.
+func (i *Index) openExistenceField() error {
+	f, err := i.createFieldIfNotExists(existenceFieldName, FieldOptions{CacheType: CacheTypeNone, CacheSize: 0})
+	if err != nil {
+		return errors.Wrap(err, "creating existence field")
+	}
+	i.existenceFld = f
+	return nil
+}
+
 // loadMeta reads meta data for the index, if any.
 func (i *Index) loadMeta() error {
 	var pb internal.IndexMeta
@@ -165,6 +188,7 @@ func (i *Index) loadMeta() error {
 
 	// Copy metadata fields.
 	i.keys = pb.Keys
+	i.trackExistence = pb.TrackExistence
 
 	return nil
 }
@@ -173,7 +197,8 @@ func (i *Index) loadMeta() error {
 func (i *Index) saveMeta() error {
 	// Marshal metadata.
 	buf, err := proto.Marshal(&internal.IndexMeta{
-		Keys: i.keys,
+		Keys:           i.keys,
+		TrackExistence: i.trackExistence,
 	})
 	if err != nil {
 		return errors.Wrap(err, "marshalling")
@@ -250,6 +275,14 @@ func (i *Index) Fields() []*Field {
 	return a
 }
 
+// existenceField returns the internal field used to track column existence.
+func (i *Index) existenceField() *Field {
+	i.mu.RLock()
+	defer i.mu.RUnlock()
+
+	return i.existenceFld
+}
+
 // recalculateCaches recalculates caches on every field in the index.
 func (i *Index) recalculateCaches() {
 	for _, field := range i.Fields() {
@@ -259,6 +292,11 @@ func (i *Index) recalculateCaches() {
 
 // CreateField creates a field.
 func (i *Index) CreateField(name string, opts ...FieldOption) (*Field, error) {
+	err := validateName(name)
+	if err != nil {
+		return nil, errors.Wrap(err, "validating name")
+	}
+
 	i.mu.Lock()
 	defer i.mu.Unlock()
 
@@ -281,6 +319,11 @@ func (i *Index) CreateField(name string, opts ...FieldOption) (*Field, error) {
 
 // CreateFieldIfNotExists creates a field with the given options if it doesn't exist.
 func (i *Index) CreateFieldIfNotExists(name string, opts ...FieldOption) (*Field, error) {
+	err := validateName(name)
+	if err != nil {
+		return nil, errors.Wrap(err, "validating name")
+	}
+
 	i.mu.Lock()
 	defer i.mu.Unlock()
 
@@ -349,7 +392,7 @@ func (i *Index) createField(name string, opt FieldOptions) (*Field, error) {
 }
 
 func (i *Index) newField(path, name string) (*Field, error) {
-	f, err := NewField(path, i.name, name, OptFieldTypeDefault())
+	f, err := newField(path, i.name, name, OptFieldTypeDefault())
 	if err != nil {
 		return nil, err
 	}
@@ -381,6 +424,18 @@ func (i *Index) DeleteField(name string) error {
 		return errors.Wrap(err, "removing directory")
 	}
 
+	// If the field being deleted is the existence field,
+	// turn off existence tracking on the index.
+	if name == existenceFieldName {
+		i.trackExistence = false
+		i.existenceFld = nil
+
+		// Update meta data on disk.
+		if err := i.saveMeta(); err != nil {
+			return errors.Wrap(err, "saving existence meta data")
+		}
+	}
+
 	// Remove reference.
 	delete(i.fields, name)
 
@@ -408,7 +463,8 @@ func (p indexInfoSlice) Less(i, j int) bool { return p[i].Name < p[j].Name }
 
 // IndexOptions represents options to set when initializing an index.
 type IndexOptions struct {
-	Keys bool `json:"keys"`
+	Keys           bool `json:"keys"`
+	TrackExistence bool `json:"trackExistence"`
 }
 
 // hasTime returns true if a contains a non-nil time.
diff --git a/index_internal_test.go b/index_internal_test.go
index 1e6d592ab..fd83fd775 100644
--- a/index_internal_test.go
+++ b/index_internal_test.go
@@ -16,10 +16,11 @@ package pilosa
 
 import (
 	"io/ioutil"
+	"testing"
 )
 
 // mustOpenIndex returns a new, opened index at a temporary path. Panic on error.
-func mustOpenIndex() *Index {
+func mustOpenIndex(opt IndexOptions) *Index {
 	path, err := ioutil.TempDir("", "pilosa-index-")
 	if err != nil {
 		panic(err)
@@ -28,6 +29,10 @@ func mustOpenIndex() *Index {
 	if err != nil {
 		panic(err)
 	}
+
+	index.keys = opt.Keys
+	index.trackExistence = opt.TrackExistence
+
 	if err := index.Open(); err != nil {
 		panic(err)
 	}
@@ -44,3 +49,40 @@ func (i *Index) reopen() error {
 	}
 	return nil
 }
+
+// Ensure that deleting the existence field is handled properly.
+func TestIndex_Existence_Delete(t *testing.T) {
+	// Create Index (with existence tracking).
+	index := mustOpenIndex(IndexOptions{TrackExistence: true})
+	defer index.Close()
+
+	// Ensure existence field has been created.
+	ef := index.Field(existenceFieldName)
+	if ef == nil {
+		t.Fatalf("expected field to have been created: %s", existenceFieldName)
+	} else if !index.trackExistence {
+		t.Fatalf("expected index.trackExistence to be true")
+	} else if index.existenceFld == nil {
+		t.Fatalf("expected index.existenceField to be non-nil")
+	}
+
+	// Delete existence field.
+	if err := index.DeleteField(existenceFieldName); err != nil {
+		t.Fatal(err)
+	}
+
+	// Re-open index.
+	if err := index.reopen(); err != nil {
+		t.Fatal(err)
+	}
+
+	// Ensure existence field no longer exists.
+	ef = index.Field(existenceFieldName)
+	if ef != nil {
+		t.Fatalf("expected field to have been deleted: %s", existenceFieldName)
+	} else if index.trackExistence {
+		t.Fatalf("expected index.trackExistence to be false")
+	} else if index.existenceFld != nil {
+		t.Fatalf("expected index.existenceField to be nil")
+	}
+}
diff --git a/internal/private.pb.go b/internal/private.pb.go
index 6247c58d4..c65049d51 100644
--- a/internal/private.pb.go
+++ b/internal/private.pb.go
@@ -62,7 +62,8 @@ var _ = math.Inf
 const _ = proto.ProtoPackageIsVersion2 // please upgrade the proto package
 
 type IndexMeta struct {
-	Keys bool `protobuf:"varint,3,opt,name=Keys,proto3" json:"Keys,omitempty"`
+	Keys           bool `protobuf:"varint,3,opt,name=Keys,proto3" json:"Keys,omitempty"`
+	TrackExistence bool `protobuf:"varint,4,opt,name=TrackExistence,proto3" json:"TrackExistence,omitempty"`
 }
 
 func (m *IndexMeta) Reset()                    { *m = IndexMeta{} }
@@ -77,6 +78,13 @@ func (m *IndexMeta) GetKeys() bool {
 	return false
 }
 
+func (m *IndexMeta) GetTrackExistence() bool {
+	if m != nil {
+		return m.TrackExistence
+	}
+	return false
+}
+
 type FieldOptions struct {
 	Type        string `protobuf:"bytes,8,opt,name=Type,proto3" json:"Type,omitempty"`
 	CacheType   string `protobuf:"bytes,3,opt,name=CacheType,proto3" json:"CacheType,omitempty"`
@@ -1051,6 +1059,16 @@ func (m *IndexMeta) MarshalTo(dAtA []byte) (int, error) {
 		}
 		i++
 	}
+	if m.TrackExistence {
+		dAtA[i] = 0x20
+		i++
+		if m.TrackExistence {
+			dAtA[i] = 1
+		} else {
+			dAtA[i] = 0
+		}
+		i++
+	}
 	return i, nil
 }
 
@@ -2300,6 +2318,9 @@ func (m *IndexMeta) Size() (n int) {
 	if m.Keys {
 		n += 2
 	}
+	if m.TrackExistence {
+		n += 2
+	}
 	return n
 }
 
@@ -2902,6 +2923,26 @@ func (m *IndexMeta) Unmarshal(dAtA []byte) error {
 				}
 			}
 			m.Keys = bool(v != 0)
+		case 4:
+			if wireType != 0 {
+				return fmt.Errorf("proto: wrong wireType = %d for field TrackExistence", wireType)
+			}
+			var v int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowPrivate
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				v |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			m.TrackExistence = bool(v != 0)
 		default:
 			iNdEx = preIndex
 			skippy, err := skipPrivate(dAtA[iNdEx:])
@@ -7143,73 +7184,74 @@ var (
 func init() { proto.RegisterFile("private.proto", fileDescriptorPrivate) }
 
 var fileDescriptorPrivate = []byte{
-	// 1077 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xac, 0x56, 0xdd, 0x6e, 0x1b, 0x45,
-	0x14, 0x66, 0x7f, 0xec, 0xda, 0xc7, 0x75, 0x9a, 0x6c, 0x69, 0xd8, 0x22, 0x94, 0x9a, 0x51, 0xa5,
-	0x9a, 0x4a, 0x84, 0xaa, 0xbd, 0xe1, 0xaf, 0x52, 0x49, 0x1c, 0x60, 0x29, 0x09, 0x65, 0x36, 0xc9,
-	0x5d, 0x2f, 0x26, 0xf6, 0xa8, 0x59, 0x65, 0xbd, 0xb3, 0xec, 0xce, 0x26, 0x71, 0x2f, 0xb8, 0x05,
-	0x89, 0x17, 0x40, 0x3c, 0x09, 0x8f, 0xc0, 0x25, 0x8f, 0x80, 0xc2, 0x8b, 0xa0, 0x39, 0x33, 0xfb,
-	0x13, 0xc7, 0x21, 0x55, 0xe0, 0x6e, 0xce, 0x77, 0xce, 0x9c, 0xf3, 0xed, 0xf9, 0x9b, 0x85, 0x7e,
-	0x9a, 0x45, 0xc7, 0x4c, 0xf2, 0xf5, 0x34, 0x13, 0x52, 0x78, 0x9d, 0x28, 0x91, 0x3c, 0x4b, 0x58,
-	0x4c, 0xee, 0x41, 0x37, 0x48, 0x26, 0xfc, 0x74, 0x9b, 0x4b, 0xe6, 0x79, 0xe0, 0x3e, 0xe7, 0xb3,
-	0xdc, 0x77, 0x06, 0xd6, 0xb0, 0x43, 0xf1, 0x4c, 0x7e, 0xb7, 0xe0, 0xe6, 0x97, 0x11, 0x8f, 0x27,
-	0xdf, 0xa5, 0x32, 0x12, 0x49, 0xee, 0xbd, 0x07, 0xdd, 0x4d, 0x36, 0x3e, 0xe4, 0xbb, 0xb3, 0x94,
-	0xa3, 0x65, 0x97, 0xd6, 0x40, 0xa5, 0x0d, 0xa3, 0xd7, 0xdc, 0x77, 0x07, 0xd6, 0xb0, 0x4f, 0x6b,
-	0xc0, 0x1b, 0x40, 0x6f, 0x37, 0x9a, 0xf2, 0xef, 0x0b, 0x96, 0xc8, 0x62, 0xea, 0xb7, 0xf0, 0x76,
-	0x13, 0x52, 0x14, 0xd0, 0x71, 0x07, 0x55, 0x78, 0xf6, 0x96, 0xc1, 0xd9, 0x8e, 0x12, 0xbf, 0x3b,
-	0xb0, 0x86, 0x0e, 0x55, 0x47, 0x44, 0xd8, 0xa9, 0x0f, 0x06, 0x61, 0xa7, 0x15, 0xf5, 0x5e, 0x83,
-	0x3a, 0x81, 0xa5, 0x60, 0x9a, 0x8a, 0x4c, 0x52, 0x9e, 0xa7, 0x22, 0xc9, 0xd1, 0xd3, 0x56, 0x96,
-	0xf9, 0x16, 0x3a, 0x57, 0x47, 0xf2, 0x23, 0x2c, 0x6f, 0xc4, 0x62, 0x7c, 0x34, 0x62, 0x92, 0x51,
-	0xfe, 0x43, 0xc1, 0x73, 0xe9, 0xbd, 0x0d, 0x2d, 0xcc, 0x89, 0xb1, 0xd3, 0x82, 0x42, 0x31, 0x0f,
-	0xbe, 0xad, 0x51, 0x14, 0x14, 0x8a, 0xf7, 0x31, 0x13, 0x2e, 0xd5, 0x82, 0x42, 0xc3, 0x43, 0x96,
-	0x4d, 0x30, 0x03, 0x2e, 0xd5, 0x82, 0xe2, 0xb8, 0x1f, 0xf1, 0x13, 0xf3, 0xd9, 0x78, 0x26, 0x01,
-	0xac, 0x34, 0xe2, 0x1b, 0x9a, 0xab, 0xd0, 0xa6, 0xe2, 0x24, 0x18, 0xe5, 0xbe, 0x35, 0x70, 0x86,
-	0x2e, 0x35, 0x12, 0x26, 0x57, 0xc4, 0xc5, 0x34, 0x51, 0x2a, 0x1b, 0x55, 0x35, 0x40, 0xee, 0x42,
-	0x0b, 0x33, 0xad, 0xbe, 0xb2, 0xbe, 0xab, 0x8e, 0xe4, 0x27, 0x0b, 0xba, 0xdb, 0xec, 0x14, 0x69,
-	0xe4, 0xde, 0x53, 0xe8, 0x84, 0x92, 0x25, 0x13, 0x45, 0x50, 0x19, 0xf5, 0x1e, 0xbf, 0xbf, 0x5e,
-	0x36, 0xc4, 0x7a, 0x65, 0xb6, 0x5e, 0xda, 0x6c, 0x25, 0x32, 0x9b, 0xd1, 0xea, 0xca, 0xbb, 0x9f,
-	0x41, 0xff, 0x9c, 0x4a, 0xc5, 0x3b, 0xe2, 0xb3, 0x32, 0xab, 0x47, 0x7c, 0xa6, 0xbe, 0xff, 0x98,
-	0xc5, 0x05, 0xc7, 0x5c, 0xb9, 0x54, 0x0b, 0x9f, 0xda, 0x1f, 0x5b, 0x64, 0x1f, 0xbc, 0xcd, 0x8c,
-	0x33, 0xc9, 0x31, 0xc8, 0x36, 0xcf, 0x73, 0xf6, 0x8a, 0x5f, 0x9e, 0x71, 0x9d, 0x45, 0xbb, 0x99,
-	0xc5, 0xaa, 0x0e, 0x4e, 0xa3, 0x0e, 0xe4, 0x21, 0x78, 0x23, 0x1e, 0x73, 0xc9, 0x4d, 0x37, 0xff,
-	0x8b, 0x5f, 0x12, 0x96, 0x1c, 0xae, 0xb6, 0xf5, 0x1e, 0x80, 0xab, 0x46, 0x03, 0x29, 0xf4, 0x1e,
-	0xdf, 0xae, 0xf3, 0x54, 0x4d, 0x0d, 0x45, 0x03, 0x12, 0x97, 0x4e, 0x91, 0xcf, 0x95, 0x1f, 0xb6,
-	0xa0, 0x95, 0x1e, 0x9a, 0x50, 0x0e, 0x86, 0x5a, 0xad, 0x43, 0x35, 0xc7, 0xcf, 0x44, 0x7b, 0x56,
-	0x7e, 0xee, 0x75, 0xa3, 0x91, 0x97, 0x06, 0x55, 0x5d, 0xb9, 0xc3, 0xa6, 0xdc, 0xdc, 0xc1, 0x73,
-	0x45, 0xc5, 0xbe, 0x9a, 0x8a, 0x72, 0xaf, 0x3a, 0x59, 0x6d, 0x0d, 0x47, 0xb9, 0x47, 0x81, 0x3c,
-	0x81, 0x76, 0x38, 0x3e, 0xe4, 0x53, 0xe6, 0x7d, 0x00, 0x37, 0x90, 0x07, 0xcf, 0x4d, 0xb3, 0xdd,
-	0x9a, 0x4b, 0x22, 0x2d, 0xf5, 0x64, 0x64, 0xf8, 0x2f, 0xe4, 0xf4, 0x00, 0xda, 0x18, 0x3d, 0xf7,
-	0xdd, 0x79, 0x37, 0x88, 0x53, 0xa3, 0x26, 0x5b, 0xe0, 0xec, 0xd1, 0x40, 0x0d, 0x11, 0x32, 0x28,
-	0xbd, 0x18, 0x49, 0xf9, 0xfe, 0x5a, 0xe4, 0xd2, 0x64, 0x03, 0xcf, 0x0a, 0x7b, 0x21, 0x32, 0x89,
-	0xa9, 0xef, 0x53, 0x3c, 0x93, 0x97, 0xe0, 0xee, 0x88, 0x09, 0xf7, 0x96, 0xc0, 0x0e, 0x46, 0xc6,
-	0x87, 0x1d, 0x8c, 0xbc, 0x7b, 0xe8, 0xde, 0xa4, 0xa6, 0x5f, 0x93, 0xd8, 0xa3, 0x01, 0xc5, 0xc0,
-	0xf7, 0xa1, 0x1f, 0xe4, 0x9b, 0x42, 0x64, 0x93, 0x28, 0x61, 0x52, 0x64, 0x66, 0x9d, 0x9e, 0x07,
-	0xc9, 0x33, 0x58, 0x56, 0xee, 0x43, 0xc9, 0x24, 0x2f, 0xeb, 0xb7, 0x0a, 0x6d, 0x85, 0x55, 0xe1,
-	0x8c, 0x84, 0x83, 0xa0, 0xec, 0xca, 0x0a, 0xa2, 0x40, 0xbe, 0xd5, 0x1e, 0xb6, 0x8e, 0x79, 0x22,
-	0x1b, 0x1d, 0x80, 0x32, 0x3a, 0xe8, 0x53, 0x2d, 0x78, 0x44, 0x7f, 0x8a, 0xe1, 0xbc, 0x54, 0x73,
-	0x56, 0x28, 0x45, 0x1d, 0xf9, 0xc5, 0x02, 0x28, 0x09, 0x15, 0x79, 0x75, 0xc5, 0xba, 0xfc, 0x8a,
-	0x37, 0x2c, 0x6b, 0x6c, 0x5a, 0x76, 0xb9, 0xb6, 0xd2, 0x38, 0x2d, 0x7b, 0xe0, 0xa3, 0xba, 0x07,
-	0x74, 0xf1, 0xee, 0xcc, 0xf5, 0x80, 0x8e, 0x5a, 0x77, 0xc2, 0x0b, 0xe8, 0x35, 0xf0, 0x85, 0xfd,
-	0xf0, 0x61, 0xd5, 0x0f, 0xf6, 0xbc, 0x4b, 0xc4, 0x8d, 0xcb, 0xb2, 0x2b, 0x9e, 0x43, 0xaf, 0x01,
-	0x2f, 0xf4, 0x38, 0x84, 0x5b, 0x5f, 0x1c, 0xb3, 0x28, 0x66, 0x07, 0xb1, 0x5e, 0x4f, 0xe5, 0x92,
-	0x9d, 0x87, 0x49, 0x04, 0xfd, 0xcd, 0xb8, 0xc8, 0x25, 0xcf, 0x8c, 0x3b, 0xb5, 0x99, 0x35, 0x50,
-	0x15, 0xaf, 0x06, 0x16, 0xd7, 0xcf, 0xbb, 0x0f, 0x2d, 0x95, 0x46, 0x3d, 0x38, 0x17, 0x73, 0xac,
-	0x95, 0x64, 0x1f, 0x3a, 0x1b, 0x61, 0xf0, 0x55, 0x26, 0x8a, 0x74, 0x21, 0xe9, 0xf2, 0xc1, 0xb4,
-	0x2f, 0x3e, 0x98, 0xce, 0x85, 0x07, 0xd3, 0xad, 0x1e, 0x4c, 0x12, 0xc2, 0x8a, 0xde, 0x57, 0x6a,
-	0x5e, 0xaf, 0xb3, 0xae, 0xca, 0xd7, 0xcc, 0x69, 0xbc, 0x66, 0x21, 0xac, 0xe8, 0xb5, 0xf4, 0x7f,
-	0x3a, 0xfd, 0xcd, 0x86, 0x15, 0xca, 0xf3, 0xe8, 0x35, 0x0f, 0x92, 0x5c, 0x66, 0xc5, 0x58, 0x6d,
-	0x1f, 0x75, 0xff, 0x1b, 0x71, 0x60, 0xb2, 0xed, 0x50, 0x2d, 0xbc, 0x49, 0xa7, 0x7b, 0x8f, 0xa0,
-	0x37, 0x3f, 0x9d, 0x17, 0x4d, 0x9b, 0x26, 0xde, 0x23, 0xb8, 0x11, 0x8a, 0x22, 0x1b, 0x57, 0xed,
-	0xdb, 0xd8, 0x88, 0x9a, 0x99, 0x56, 0xd3, 0xd2, 0xac, 0x31, 0x1a, 0xad, 0x2b, 0x46, 0xe3, 0xe9,
-	0x5c, 0x2b, 0xf9, 0x6d, 0xbc, 0xf0, 0x4e, 0x7d, 0xe1, 0x9c, 0x9a, 0x9e, 0xb7, 0x26, 0x3f, 0x5b,
-	0x70, 0xb3, 0x49, 0xe1, 0x8d, 0x06, 0xb7, 0xaa, 0x88, 0xbd, 0xb0, 0x22, 0xce, 0xa2, 0x8a, 0xb8,
-	0x75, 0x45, 0xea, 0x87, 0xb9, 0xd5, 0x78, 0x98, 0xc9, 0x11, 0xdc, 0xbd, 0x50, 0xa6, 0x4d, 0x31,
-	0x4d, 0x55, 0x3f, 0xfc, 0x87, 0x72, 0xa9, 0x95, 0x96, 0x65, 0xa6, 0x50, 0x5d, 0xaa, 0x05, 0xf2,
-	0x09, 0xdc, 0x09, 0xb9, 0x6c, 0x14, 0xa9, 0xec, 0xb6, 0x01, 0x38, 0x3b, 0xfc, 0xe4, 0x92, 0xcf,
-	0x57, 0x2a, 0xf2, 0x39, 0xf8, 0x7b, 0xe9, 0x84, 0x49, 0x7e, 0xad, 0xdb, 0x1b, 0xd0, 0xd9, 0x15,
-	0xa9, 0x88, 0xc5, 0xab, 0xd9, 0x15, 0x53, 0xef, 0xc3, 0x0d, 0xbd, 0xbf, 0xf5, 0x1a, 0xe9, 0xd2,
-	0x52, 0x24, 0xb7, 0x55, 0x43, 0x8f, 0x59, 0x3c, 0x2e, 0x62, 0x45, 0x43, 0xfd, 0xb4, 0xe5, 0x1b,
-	0xcb, 0x7f, 0x9c, 0xad, 0x59, 0x7f, 0x9e, 0xad, 0x59, 0x7f, 0x9d, 0xad, 0x59, 0xbf, 0xfe, 0xbd,
-	0xf6, 0xd6, 0x41, 0x1b, 0x7f, 0xd6, 0x9f, 0xfc, 0x13, 0x00, 0x00, 0xff, 0xff, 0x7e, 0x7c, 0x6d,
-	0x22, 0xbd, 0x0b, 0x00, 0x00,
+	// 1095 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xac, 0x56, 0xdd, 0x6e, 0xdc, 0x44,
+	0x14, 0xc6, 0x3f, 0xbb, 0xd9, 0x3d, 0xdb, 0x4d, 0x13, 0x97, 0x06, 0x17, 0xa1, 0x10, 0x46, 0x15,
+	0x0d, 0x95, 0x08, 0x55, 0x7b, 0xc3, 0x5f, 0xa5, 0x92, 0x6c, 0x28, 0xa6, 0x24, 0x94, 0x71, 0x92,
+	0xbb, 0x5e, 0x4c, 0x76, 0x47, 0x8d, 0x15, 0xaf, 0xc7, 0xd8, 0xe3, 0x24, 0xdb, 0x0b, 0x6e, 0x41,
+	0xe2, 0x05, 0x10, 0x4f, 0xc2, 0x23, 0x70, 0xc9, 0x23, 0xa0, 0xf0, 0x22, 0x68, 0xce, 0x8c, 0x7f,
+	0xb2, 0xd9, 0xb0, 0x55, 0xe8, 0xdd, 0x9c, 0xef, 0x9c, 0x39, 0xe7, 0x9b, 0xf3, 0x67, 0x43, 0x3f,
+	0xcd, 0xa2, 0x13, 0x26, 0xf9, 0x46, 0x9a, 0x09, 0x29, 0xbc, 0x4e, 0x94, 0x48, 0x9e, 0x25, 0x2c,
+	0x26, 0x4f, 0xa1, 0x1b, 0x24, 0x23, 0x7e, 0xb6, 0xc3, 0x25, 0xf3, 0x3c, 0x70, 0x9f, 0xf1, 0x49,
+	0xee, 0x3b, 0x6b, 0xd6, 0x7a, 0x87, 0xe2, 0xd9, 0xfb, 0x10, 0x16, 0xf7, 0x32, 0x36, 0x3c, 0xde,
+	0x3e, 0x8b, 0x72, 0xc9, 0x93, 0x21, 0xf7, 0x5d, 0xd4, 0x4e, 0xa1, 0xe4, 0x0f, 0x0b, 0x6e, 0x7c,
+	0x1d, 0xf1, 0x78, 0xf4, 0x7d, 0x2a, 0x23, 0x91, 0xe4, 0xde, 0x7b, 0xd0, 0xdd, 0x62, 0xc3, 0x23,
+	0xbe, 0x37, 0x49, 0x39, 0x7a, 0xec, 0xd2, 0x1a, 0xa8, 0xb4, 0x61, 0xf4, 0x4a, 0x7b, 0xec, 0xd3,
+	0x1a, 0xf0, 0xd6, 0xa0, 0xb7, 0x17, 0x8d, 0xf9, 0x0f, 0x05, 0x4b, 0x64, 0x31, 0xf6, 0x5b, 0x78,
+	0xbb, 0x09, 0x29, 0xaa, 0xe8, 0xb8, 0x83, 0x2a, 0x3c, 0x7b, 0x4b, 0xe0, 0xec, 0x44, 0x89, 0xdf,
+	0x5d, 0xb3, 0xd6, 0x1d, 0xaa, 0x8e, 0x88, 0xb0, 0x33, 0x1f, 0x0c, 0xc2, 0xce, 0xaa, 0x27, 0xf6,
+	0xea, 0x27, 0x12, 0x02, 0x8b, 0xc1, 0x38, 0x15, 0x99, 0xa4, 0x3c, 0x4f, 0x45, 0x92, 0xa3, 0xa7,
+	0xed, 0x2c, 0xf3, 0x2d, 0x74, 0xae, 0x8e, 0xe4, 0x27, 0x58, 0xda, 0x8c, 0xc5, 0xf0, 0x78, 0xc0,
+	0x24, 0xa3, 0xfc, 0xc7, 0x82, 0xe7, 0xd2, 0x7b, 0x1b, 0x5a, 0x98, 0x3b, 0x63, 0xa7, 0x05, 0x85,
+	0x62, 0x1e, 0x7c, 0x5b, 0xa3, 0x28, 0x28, 0x14, 0xef, 0x63, 0x26, 0x5c, 0xaa, 0x05, 0x85, 0x86,
+	0x47, 0x2c, 0x1b, 0x61, 0x06, 0x5c, 0xaa, 0x05, 0xc5, 0xf1, 0x20, 0xe2, 0xa7, 0xe6, 0xd9, 0x78,
+	0x26, 0x01, 0x2c, 0x37, 0xe2, 0x1b, 0x9a, 0x2b, 0xd0, 0xa6, 0xe2, 0x34, 0x18, 0xe4, 0xbe, 0xb5,
+	0xe6, 0xac, 0xbb, 0xd4, 0x48, 0x98, 0x5c, 0x11, 0x17, 0xe3, 0x44, 0xa9, 0x6c, 0x54, 0xd5, 0x00,
+	0xb9, 0x03, 0x2d, 0xcc, 0xb4, 0x7a, 0x65, 0x7d, 0x57, 0x1d, 0xc9, 0xcf, 0x16, 0x74, 0x77, 0xd8,
+	0x19, 0xd2, 0xc8, 0xbd, 0xc7, 0xd0, 0x09, 0x25, 0x4b, 0x46, 0x8a, 0xa0, 0x32, 0xea, 0x3d, 0xfc,
+	0x60, 0xa3, 0x6c, 0x9c, 0x8d, 0xca, 0x6c, 0xa3, 0xb4, 0xd9, 0x4e, 0x64, 0x36, 0xa1, 0xd5, 0x95,
+	0x77, 0xbf, 0x80, 0xfe, 0x05, 0x95, 0x8a, 0x77, 0xcc, 0x27, 0x65, 0x56, 0x8f, 0xf9, 0x44, 0xbd,
+	0xff, 0x84, 0xc5, 0x05, 0xc7, 0x5c, 0xb9, 0x54, 0x0b, 0x9f, 0xdb, 0x9f, 0x5a, 0xe4, 0x00, 0xbc,
+	0xad, 0x8c, 0x33, 0xc9, 0x31, 0xc8, 0x0e, 0xcf, 0x73, 0xf6, 0x92, 0x5f, 0x9d, 0x71, 0x9d, 0x45,
+	0xbb, 0x99, 0xc5, 0xaa, 0x0e, 0x4e, 0xa3, 0x0e, 0xe4, 0x3e, 0x78, 0x03, 0x1e, 0x73, 0xc9, 0x4d,
+	0xd7, 0xff, 0x87, 0x5f, 0x12, 0x96, 0x1c, 0xe6, 0xdb, 0x7a, 0xf7, 0xc0, 0x55, 0x23, 0x84, 0x14,
+	0x7a, 0x0f, 0x6f, 0xd5, 0x79, 0xaa, 0xa6, 0x8b, 0xa2, 0x01, 0x89, 0x4b, 0xa7, 0xc8, 0x67, 0xee,
+	0xc3, 0x66, 0xb4, 0xd2, 0x7d, 0x13, 0xca, 0xc1, 0x50, 0x2b, 0x75, 0xa8, 0xe6, 0xf8, 0x99, 0x68,
+	0x4f, 0xca, 0xe7, 0x5e, 0x37, 0x1a, 0x79, 0x61, 0x50, 0xd5, 0x95, 0xbb, 0x6c, 0xcc, 0xcd, 0x1d,
+	0x3c, 0x57, 0x54, 0xec, 0xf9, 0x54, 0x94, 0x7b, 0xd5, 0xc9, 0x6a, 0xbb, 0x38, 0xca, 0x3d, 0x0a,
+	0xe4, 0x11, 0xb4, 0xc3, 0xe1, 0x11, 0x1f, 0x33, 0xef, 0x23, 0x58, 0x40, 0x1e, 0x3c, 0x37, 0xcd,
+	0x76, 0x73, 0x2a, 0x89, 0xb4, 0xd4, 0x93, 0x81, 0xe1, 0x3f, 0x93, 0xd3, 0x3d, 0x68, 0x63, 0xf4,
+	0xdc, 0x77, 0xa7, 0xdd, 0x20, 0x4e, 0x8d, 0x9a, 0x6c, 0x83, 0xb3, 0x4f, 0x03, 0x35, 0x44, 0xc8,
+	0xa0, 0xf4, 0x62, 0x24, 0xe5, 0xfb, 0x1b, 0x91, 0x4b, 0x93, 0x0d, 0x3c, 0x2b, 0xec, 0xb9, 0xc8,
+	0x24, 0xa6, 0xbe, 0x4f, 0xf1, 0x4c, 0x5e, 0x80, 0xbb, 0x2b, 0x46, 0xdc, 0x5b, 0x04, 0x3b, 0x18,
+	0x18, 0x1f, 0x76, 0x30, 0xf0, 0xde, 0x47, 0xf7, 0x26, 0x35, 0xfd, 0x9a, 0xc4, 0x3e, 0x0d, 0x28,
+	0x06, 0xbe, 0x0b, 0xfd, 0x20, 0xdf, 0x12, 0x22, 0x1b, 0x45, 0x09, 0x93, 0x22, 0x33, 0x6b, 0xf7,
+	0x22, 0x48, 0x9e, 0xc0, 0x92, 0x72, 0x1f, 0x4a, 0x26, 0x79, 0x59, 0xbf, 0x15, 0x68, 0x2b, 0xac,
+	0x0a, 0x67, 0x24, 0x1c, 0x04, 0x65, 0x57, 0x56, 0x10, 0x05, 0xf2, 0x9d, 0xf6, 0xb0, 0x7d, 0xc2,
+	0x13, 0xd9, 0xe8, 0x00, 0x94, 0xd1, 0x41, 0x9f, 0x6a, 0xc1, 0x23, 0xfa, 0x29, 0x86, 0xf3, 0x62,
+	0xcd, 0x59, 0xa1, 0x14, 0x75, 0xe4, 0x57, 0x0b, 0xa0, 0x24, 0x54, 0xe4, 0xd5, 0x15, 0xeb, 0xea,
+	0x2b, 0xde, 0x7a, 0x59, 0x63, 0xd3, 0xb2, 0x4b, 0xb5, 0x95, 0xc6, 0x69, 0xd9, 0x03, 0x9f, 0xd4,
+	0x3d, 0xa0, 0x8b, 0x77, 0x7b, 0xaa, 0x07, 0x74, 0xd4, 0xba, 0x13, 0x9e, 0x43, 0xaf, 0x81, 0xcf,
+	0xec, 0x87, 0x8f, 0xab, 0x7e, 0xb0, 0xa7, 0x5d, 0x22, 0x6e, 0x5c, 0x96, 0x5d, 0xf1, 0x0c, 0x7a,
+	0x0d, 0x78, 0xa6, 0xc7, 0x75, 0xb8, 0xf9, 0xd5, 0x09, 0x8b, 0x62, 0x76, 0x18, 0xeb, 0xf5, 0x54,
+	0x2e, 0xd9, 0x69, 0x98, 0x44, 0xd0, 0xdf, 0x8a, 0x8b, 0x5c, 0xf2, 0xcc, 0xb8, 0x53, 0x9b, 0x59,
+	0x03, 0x55, 0xf1, 0x6a, 0x60, 0x76, 0xfd, 0xbc, 0xbb, 0xd0, 0x52, 0x69, 0xd4, 0x83, 0x73, 0x39,
+	0xc7, 0x5a, 0x49, 0x0e, 0xa0, 0xb3, 0x19, 0x06, 0x4f, 0x33, 0x51, 0xa4, 0x33, 0x49, 0x97, 0x1f,
+	0x4c, 0xfb, 0xf2, 0x07, 0xd3, 0xb9, 0xf4, 0xc1, 0x74, 0xab, 0x0f, 0x26, 0x09, 0x61, 0x59, 0xef,
+	0x2b, 0x35, 0xaf, 0xd7, 0x59, 0x57, 0xe5, 0xd7, 0xcc, 0x69, 0x7c, 0xcd, 0x42, 0x58, 0xd6, 0x6b,
+	0xe9, 0x4d, 0x3a, 0xfd, 0xdd, 0x86, 0x65, 0xca, 0xf3, 0xe8, 0x15, 0x0f, 0x92, 0x5c, 0x66, 0xc5,
+	0x50, 0x6d, 0x1f, 0x75, 0xff, 0x5b, 0x71, 0x68, 0xb2, 0xed, 0x50, 0x2d, 0xbc, 0x4e, 0xa7, 0x7b,
+	0x0f, 0xa0, 0x37, 0x3d, 0x9d, 0x97, 0x4d, 0x9b, 0x26, 0xde, 0x03, 0x58, 0x08, 0x45, 0x91, 0x0d,
+	0xab, 0xf6, 0x6d, 0x6c, 0x44, 0xcd, 0x4c, 0xab, 0x69, 0x69, 0xd6, 0x18, 0x8d, 0xd6, 0x9c, 0xd1,
+	0x78, 0x3c, 0xd5, 0x4a, 0x7e, 0x1b, 0x2f, 0xbc, 0x53, 0x5f, 0xb8, 0xa0, 0xa6, 0x17, 0xad, 0xc9,
+	0x2f, 0x16, 0xdc, 0x68, 0x52, 0x78, 0xad, 0xc1, 0xad, 0x2a, 0x62, 0xcf, 0xac, 0x88, 0x33, 0xab,
+	0x22, 0x6e, 0x5d, 0x91, 0xfa, 0xc3, 0xdc, 0x6a, 0x7c, 0x98, 0xc9, 0x31, 0xdc, 0xb9, 0x54, 0xa6,
+	0x2d, 0x31, 0x4e, 0x55, 0x3f, 0xfc, 0x8f, 0x72, 0xa9, 0x95, 0x96, 0x65, 0xa6, 0x50, 0x5d, 0xaa,
+	0x05, 0xf2, 0x19, 0xdc, 0x0e, 0xb9, 0x6c, 0x14, 0xa9, 0xec, 0xb6, 0x35, 0x70, 0x76, 0xf9, 0xe9,
+	0x15, 0xcf, 0x57, 0x2a, 0xf2, 0x25, 0xf8, 0xfb, 0xe9, 0x88, 0x49, 0x7e, 0xad, 0xdb, 0x9b, 0xd0,
+	0xd9, 0x13, 0xa9, 0x88, 0xc5, 0xcb, 0xc9, 0x9c, 0xa9, 0xf7, 0x61, 0x41, 0xef, 0x6f, 0xbd, 0x46,
+	0xba, 0xb4, 0x14, 0xc9, 0x2d, 0xd5, 0xd0, 0x43, 0x16, 0x0f, 0x8b, 0x58, 0xd1, 0x50, 0x3f, 0x6d,
+	0xf9, 0xe6, 0xd2, 0x9f, 0xe7, 0xab, 0xd6, 0x5f, 0xe7, 0xab, 0xd6, 0xdf, 0xe7, 0xab, 0xd6, 0x6f,
+	0xff, 0xac, 0xbe, 0x75, 0xd8, 0xc6, 0x9f, 0xfa, 0x47, 0xff, 0x06, 0x00, 0x00, 0xff, 0xff, 0x31,
+	0x07, 0xf3, 0xac, 0xe5, 0x0b, 0x00, 0x00,
 }
diff --git a/internal/private.proto b/internal/private.proto
index 95f211a81..88d16363f 100644
--- a/internal/private.proto
+++ b/internal/private.proto
@@ -4,6 +4,7 @@ package internal;
 
 message IndexMeta {
 	bool Keys = 3;
+	bool TrackExistence = 4;
 }
 
 message FieldOptions {
diff --git a/pilosa.go b/pilosa.go
index 45d77a9f3..7378eb628 100644
--- a/pilosa.go
+++ b/pilosa.go
@@ -49,6 +49,8 @@ var (
 	ErrName  = errors.New("invalid index or field name, must match [a-z0-9_-]")
 	ErrLabel = errors.New("invalid row or column label, must match [A-Za-z0-9_-]")
 
+	ErrReservedName = errors.New("reserved index or field name")
+
 	// ErrFragmentNotFound is returned when a fragment does not exist.
 	ErrFragmentNotFound = errors.New("fragment not found")
 	ErrQueryRequired    = errors.New("query required")
@@ -125,6 +127,9 @@ const TimeFormat = "2006-01-02T15:04"
 
 // validateName ensures that the name is a valid format.
 func validateName(name string) error {
+	if name == existenceFieldName {
+		return ErrReservedName
+	}
 	if !nameRegexp.Match([]byte(name)) {
 		return ErrName
 	}
diff --git a/pilosa_internal_test.go b/pilosa_internal_test.go
index 139d5c2b7..96dae1433 100644
--- a/pilosa_internal_test.go
+++ b/pilosa_internal_test.go
@@ -34,6 +34,7 @@ func TestValidateNameInvalid(t *testing.T) {
 	names := []string{
 		"", "'", "^", "/", "\\", "A", "*", "a:b", "valid?no", "yüce", "1", "_", "-",
 		"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa1",
+		"exists",
 	}
 	for _, name := range names {
 		if validateName(name) == nil {
diff --git a/test/holder.go b/test/holder.go
index 80778fe2a..8d080e493 100644
--- a/test/holder.go
+++ b/test/holder.go
@@ -91,6 +91,20 @@ func (h *Holder) Row(index, field string, rowID uint64) *pilosa.Row {
 	return row
 }
 
+// ReadRow returns a Row for a given field. If the field does not exist,
+// it panics rather than creating the field.
+func (h *Holder) ReadRow(index, field string, rowID uint64) *pilosa.Row {
+	f := h.Holder.Field(index, field)
+	if f == nil {
+		panic(pilosa.ErrFieldNotFound)
+	}
+	row, err := f.Row(rowID)
+	if err != nil {
+		panic(err)
+	}
+	return row
+}
+
 func (h *Holder) RowAttrStore(index, field string) pilosa.AttrStore {
 	idx := h.MustCreateIndexIfNotExists(index, pilosa.IndexOptions{})
 	f, err := idx.CreateFieldIfNotExists(field, pilosa.OptFieldTypeDefault())
diff --git a/test/pilosa.go b/test/pilosa.go
index e7111ad92..9dbd78057 100644
--- a/test/pilosa.go
+++ b/test/pilosa.go
@@ -18,7 +18,6 @@ import (
 	"bytes"
 	"context"
 	"fmt"
-	"io"
 	"io/ioutil"
 	gohttp "net/http"
 	"os"
@@ -40,10 +39,6 @@ type Command struct {
 	*server.Command
 
 	commandOptions []server.CommandOption
-
-	stdin  bytes.Buffer
-	stdout bytes.Buffer
-	stderr bytes.Buffer
 }
 
 func OptAllowedOrigins(origins []string) server.CommandOption {
@@ -65,17 +60,15 @@ func newCommand(opts ...server.CommandOption) *Command {
 	// beginning of the option slice so that it can be overridden by user-passed
 	// options.
 	opts = append([]server.CommandOption{server.OptCommandCloseTimeout(time.Millisecond * 2)}, opts...)
-	m := &Command{Command: server.NewCommand(os.Stdin, os.Stdout, os.Stderr, opts...), commandOptions: opts}
+	m := &Command{commandOptions: opts}
+	m.Command = server.NewCommand(bytes.NewReader(nil), ioutil.Discard, ioutil.Discard, opts...)
 	m.Config.DataDir = path
 	m.Config.Bind = "http://localhost:0"
 	m.Config.Cluster.Disabled = true
-	m.Command.Stdin = &m.stdin
-	m.Command.Stdout = &m.stdout
-	m.Command.Stderr = &m.stderr
 
 	if testing.Verbose() {
-		m.Command.Stdout = io.MultiWriter(os.Stdout, m.Command.Stdout)
-		m.Command.Stderr = io.MultiWriter(os.Stderr, m.Command.Stderr)
+		m.Command.Stdout = os.Stdout
+		m.Command.Stderr = os.Stderr
 	}
 
 	return m
@@ -120,7 +113,7 @@ func (m *Command) Reopen() error {
 
 	// Create new main with the same config.
 	config := m.Command.Config
-	m.Command = server.NewCommand(os.Stdin, os.Stdout, os.Stderr, m.commandOptions...)
+	m.Command = server.NewCommand(bytes.NewReader(nil), ioutil.Discard, ioutil.Discard, m.commandOptions...)
 	m.Command.Config = config
 
 	// Run new program.