diff --git a/go/vt/key/destination.go b/go/vt/key/destination.go
index 235f561c2d7..c4fb37b7a9d 100644
--- a/go/vt/key/destination.go
+++ b/go/vt/key/destination.go
@@ -42,14 +42,6 @@ type Destination interface {
 	// The returned error must be generated by vterrors.
 	Resolve([]*topodatapb.ShardReference, func(shard string) error) error
 
-	// IsUnique returns true if this is a single destination.
-	// It returns false if this type can map to multiple destinations.
-	//
-	// TODO(alainjobart) That is just a method I think will be useful.
-	// Mainly, in v3, once we Map(), each returned result should
-	// be IsUnique=true for a Unique vindex.
-	IsUnique() bool
-
 	// String returns a printable version of the Destination.
 	String() string
 }
@@ -75,11 +67,6 @@ func DestinationsString(destinations []Destination) string {
 // It implements the Destination interface.
 type DestinationShard string
 
-// IsUnique is part of the Destination interface.
-func (d DestinationShard) IsUnique() bool {
-	return true
-}
-
 // Resolve is part of the Destination interface.
 func (d DestinationShard) Resolve(allShards []*topodatapb.ShardReference, addShard func(shard string) error) error {
 	return addShard(string(d))
@@ -98,11 +85,6 @@ func (d DestinationShard) String() string {
 // It implements the Destination interface.
 type DestinationShards []string
 
-// IsUnique is part of the Destination interface.
-func (d DestinationShards) IsUnique() bool {
-	return false
-}
-
 // Resolve is part of the Destination interface.
 func (d DestinationShards) Resolve(allShards []*topodatapb.ShardReference, addShard func(shard string) error) error {
 	for _, shard := range d {
@@ -134,11 +116,6 @@ type DestinationExactKeyRange struct {
 	KeyRange *topodatapb.KeyRange
 }
 
-// IsUnique is part of the Destination interface.
-func (d DestinationExactKeyRange) IsUnique() bool {
-	return true
-}
-
 // Resolve is part of the Destination interface.
 func (d DestinationExactKeyRange) Resolve(allShards []*topodatapb.ShardReference, addShard func(shard string) error) error {
 	return processExactKeyRange(allShards, d.KeyRange, addShard)
@@ -188,11 +165,6 @@ func processExactKeyRange(allShards []*topodatapb.ShardReference, kr *topodatapb
 // It implements the Destination interface.
 type DestinationExactKeyRanges []*topodatapb.KeyRange
 
-// IsUnique is part of the Destination interface.
-func (d DestinationExactKeyRanges) IsUnique() bool {
-	return false
-}
-
 // Resolve is part of the Destination interface.
 func (d DestinationExactKeyRanges) Resolve(allShards []*topodatapb.ShardReference, addShard func(shard string) error) error {
 	for _, kr := range d {
@@ -231,11 +203,6 @@ type DestinationKeyRange struct {
 	KeyRange *topodatapb.KeyRange
 }
 
-// IsUnique is part of the Destination interface.
-func (d DestinationKeyRange) IsUnique() bool {
-	return true
-}
-
 // Resolve is part of the Destination interface.
 func (d DestinationKeyRange) Resolve(allShards []*topodatapb.ShardReference, addShard func(shard string) error) error {
 	return processKeyRange(allShards, d.KeyRange, addShard)
@@ -267,11 +234,6 @@ func processKeyRange(allShards []*topodatapb.ShardReference, kr *topodatapb.KeyR
 // It implements the Destination interface.
 type DestinationKeyRanges []*topodatapb.KeyRange
 
-// IsUnique is part of the Destination interface.
-func (d DestinationKeyRanges) IsUnique() bool {
-	return false
-}
-
 // Resolve is part of the Destination interface.
 func (d DestinationKeyRanges) Resolve(allShards []*topodatapb.ShardReference, addShard func(shard string) error) error {
 	for _, kr := range d {
@@ -304,11 +266,6 @@ func (d DestinationKeyRanges) String() string {
 // It implements the Destination interface.
 type DestinationKeyspaceID []byte
 
-// IsUnique is part of the Destination interface.
-func (d DestinationKeyspaceID) IsUnique() bool {
-	return true
-}
-
 // Resolve is part of the Destination interface.
 func (d DestinationKeyspaceID) Resolve(allShards []*topodatapb.ShardReference, addShard func(shard string) error) error {
 	shard, err := GetShardForKeyspaceID(allShards, d)
@@ -345,11 +302,6 @@ func GetShardForKeyspaceID(allShards []*topodatapb.ShardReference, keyspaceID []
 // It implements the Destination interface.
 type DestinationKeyspaceIDs [][]byte
 
-// IsUnique is part of the Destination interface.
-func (d DestinationKeyspaceIDs) IsUnique() bool {
-	return false
-}
-
 // Resolve is part of the Destination interface.
 func (d DestinationKeyspaceIDs) Resolve(allShards []*topodatapb.ShardReference, addShard func(shard string) error) error {
 	for _, ksid := range d {
@@ -400,11 +352,6 @@ func (dp DestinationAnyShardPickerRandomShard) PickShard(shardCount int) int {
 // It implements the Destination interface.
 type DestinationAnyShard struct{}
 
-// IsUnique is part of the Destination interface.
-func (d DestinationAnyShard) IsUnique() bool {
-	return true
-}
-
 // Resolve is part of the Destination interface.
 func (d DestinationAnyShard) Resolve(allShards []*topodatapb.ShardReference, addShard func(shard string) error) error {
 	if len(allShards) == 0 {
@@ -427,11 +374,6 @@ func (d DestinationAnyShard) String() string {
 // It implements the Destination interface.
 type DestinationAllShards struct{}
 
-// IsUnique is part of the Destination interface.
-func (d DestinationAllShards) IsUnique() bool {
-	return false
-}
-
 // Resolve is part of the Destination interface.
 func (d DestinationAllShards) Resolve(allShards []*topodatapb.ShardReference, addShard func(shard string) error) error {
 	for _, shard := range allShards {
@@ -456,11 +398,6 @@ func (d DestinationAllShards) String() string {
 // It implements the Destination interface.
 type DestinationNone struct{}
 
-// IsUnique is part of the Destination interface.
-func (d DestinationNone) IsUnique() bool {
-	return true
-}
-
 // Resolve is part of the Destination interface.
 func (d DestinationNone) Resolve(allShards []*topodatapb.ShardReference, addShard func(shard string) error) error {
 	return nil