From 45cd48c1b7a6c7a5bbfe65c9c4cf3554fbf78734 Mon Sep 17 00:00:00 2001
From: Matt Jaffee <matthew.jaffee@gmail.com>
Date: Mon, 17 Dec 2018 15:44:50 -0600
Subject: [PATCH] change exists field to _exists

---
 executor_test.go        | 12 ++++++------
 holder.go               |  2 +-
 http/client_test.go     |  4 ++--
 pilosa.go               |  5 -----
 pilosa_internal_test.go |  5 ++---
 5 files changed, 11 insertions(+), 17 deletions(-)

diff --git a/executor_test.go b/executor_test.go
index 3c54fbefb..141533d7f 100644
--- a/executor_test.go
+++ b/executor_test.go
@@ -2163,10 +2163,10 @@ func TestExecutor_Execute_Existence(t *testing.T) {
 			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 {
+		if res, err := c[0].API.Query(context.Background(), &pilosa.QueryRequest{Index: "i", Query: `Not(Row(f=10))`}); 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)
+		} else if bits := res.Results[0].(*pilosa.Row).Columns(); !reflect.DeepEqual(bits, []uint64{ShardWidth + 2}) {
+			t.Fatalf("unexpected columns after Not: %+v", bits)
 		}
 
 		// Reopen cluster to ensure existence field is reloaded.
@@ -2174,10 +2174,10 @@ func TestExecutor_Execute_Existence(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		if res, err := c[0].API.Query(context.Background(), &pilosa.QueryRequest{Index: "i", Query: `Row(exists=0)`}); err != nil {
+		if res, err := c[0].API.Query(context.Background(), &pilosa.QueryRequest{Index: "i", Query: `Not(Row(f=10))`}); 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)
+		} else if bits := res.Results[0].(*pilosa.Row).Columns(); !reflect.DeepEqual(bits, []uint64{ShardWidth + 2}) {
+			t.Fatalf("unexpected columns after reopen: %+v", bits)
 		}
 	})
 }
diff --git a/holder.go b/holder.go
index 9e58e8057..39fef3595 100644
--- a/holder.go
+++ b/holder.go
@@ -43,7 +43,7 @@ const (
 	fileLimit = 262144 // (512^2)
 
 	// existenceFieldName is the name of the internal field used to store existence values.
-	existenceFieldName = "exists"
+	existenceFieldName = "_exists"
 )
 
 // Holder represents a container for indexes.
diff --git a/http/client_test.go b/http/client_test.go
index fee3754df..79aa2a2ea 100644
--- a/http/client_test.go
+++ b/http/client_test.go
@@ -900,7 +900,7 @@ func TestClient_ImportExistence(t *testing.T) {
 		}
 
 		// Verify existence.
-		if a := hldr.ReadRow(idxName, "exists", 0).Columns(); !reflect.DeepEqual(a, []uint64{1, 5, 6}) {
+		if a := hldr.ReadRow(idxName, "_exists", 0).Columns(); !reflect.DeepEqual(a, []uint64{1, 5, 6}) {
 			t.Fatalf("unexpected existence columns: %+v", a)
 		}
 	})
@@ -935,7 +935,7 @@ func TestClient_ImportExistence(t *testing.T) {
 		}
 
 		// Verify existence.
-		if a := hldr.ReadRow(idxName, "exists", 0).Columns(); !reflect.DeepEqual(a, []uint64{1, 2, 3}) {
+		if a := hldr.ReadRow(idxName, "_exists", 0).Columns(); !reflect.DeepEqual(a, []uint64{1, 2, 3}) {
 			t.Fatalf("unexpected existence columns: %+v", a)
 		}
 	})
diff --git a/pilosa.go b/pilosa.go
index 56e8e0f9e..fe61d8969 100644
--- a/pilosa.go
+++ b/pilosa.go
@@ -49,8 +49,6 @@ 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")
@@ -131,9 +129,6 @@ 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 e1bea3199..40e33ac4b 100644
--- a/pilosa_internal_test.go
+++ b/pilosa_internal_test.go
@@ -20,7 +20,7 @@ import (
 
 func TestValidateName(t *testing.T) {
 	names := []string{
-		"a", "ab", "ab1", "b-c", "d_e",
+		"a", "ab", "ab1", "b-c", "d_e", "exists",
 		"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
 	}
 	for _, name := range names {
@@ -33,8 +33,7 @@ func TestValidateName(t *testing.T) {
 func TestValidateNameInvalid(t *testing.T) {
 	names := []string{
 		"", "'", "^", "/", "\\", "A", "*", "a:b", "valid?no", "yüce", "1", "_", "-",
-		"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa1",
-		"exists",
+		"aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa1", "_exists",
 	}
 	for _, name := range names {
 		if validateName(name) == nil {