diff --git a/go/vt/vtgate/planbuilder/dptable.go b/go/vt/vtgate/planbuilder/dptable.go
new file mode 100644
index 00000000000..c65870cddc2
--- /dev/null
+++ b/go/vt/vtgate/planbuilder/dptable.go
@@ -0,0 +1,59 @@
+/*
+Copyright 2020 The Vitess Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package planbuilder
+
+import "vitess.io/vitess/go/vt/vtgate/semantics"
+
+// dpTable, is the hashmap we store results in during
+// the dynamic programming part of query planning
+type dpTable struct {
+	// hash map of the best solution for each seen table
+	m map[semantics.TableSet]joinTree
+
+	highest semantics.TableSet
+}
+
+func makeDPTable() *dpTable {
+	return &dpTable{
+		m: map[semantics.TableSet]joinTree{},
+	}
+}
+
+func (dpt *dpTable) add(tree joinTree) {
+	solved := tree.solves()
+	if dpt.highest < solved {
+		dpt.highest = solved
+	}
+	dpt.m[solved] = tree
+}
+
+func (dpt *dpTable) planFor(id semantics.TableSet) joinTree {
+	return dpt.m[id]
+}
+
+func (dpt *dpTable) bitSetsOfSize(wanted int) []joinTree {
+	var result []joinTree
+	for x := semantics.TableSet(1); x <= dpt.highest; x++ {
+		if x.NumberOfTables() == wanted {
+			t, ok := dpt.m[x]
+			if ok {
+				result = append(result, t)
+			}
+		}
+	}
+	return result
+}
diff --git a/go/vt/vtgate/planbuilder/dptable_test.go b/go/vt/vtgate/planbuilder/dptable_test.go
new file mode 100644
index 00000000000..e0e10e1b153
--- /dev/null
+++ b/go/vt/vtgate/planbuilder/dptable_test.go
@@ -0,0 +1,63 @@
+/*
+Copyright 2020 The Vitess Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package planbuilder
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"vitess.io/vitess/go/vt/vtgate/semantics"
+)
+
+type fakePlan struct {
+	solve semantics.TableSet
+}
+
+func (f *fakePlan) solves() semantics.TableSet {
+	return f.solve
+}
+
+func (f *fakePlan) cost() int {
+	return 1
+}
+
+var _ joinTree = (*fakePlan)(nil)
+
+func TestDpTableSizeOf(t *testing.T) {
+	dpTable := makeDPTable()
+
+	a := semantics.TableSet(1)
+	b := semantics.TableSet(2)
+
+	t1 := &fakePlan{solve: a}
+	t2 := &fakePlan{solve: b}
+	t3 := &fakePlan{solve: a.Merge(b)}
+
+	dpTable.add(t1)
+	dpTable.add(t2)
+	dpTable.add(t3)
+
+	size1 := dpTable.bitSetsOfSize(1)
+	assert.Equal(t, []joinTree{t1, t2}, size1, "size 1")
+
+	size2 := dpTable.bitSetsOfSize(2)
+	assert.Equal(t, []joinTree{t3}, size2, "size 2")
+	assert.Equal(t, t1, dpTable.planFor(a))
+	assert.Equal(t, t2, dpTable.planFor(b))
+	assert.Equal(t, t3, dpTable.planFor(a.Merge(b)))
+}
diff --git a/go/vt/vtgate/planbuilder/route_planning.go b/go/vt/vtgate/planbuilder/route_planning.go
index 9dc37fc283d..60144023284 100644
--- a/go/vt/vtgate/planbuilder/route_planning.go
+++ b/go/vt/vtgate/planbuilder/route_planning.go
@@ -112,45 +112,8 @@ type (
 
 		lhs, rhs joinTree
 	}
-	dpTableT struct {
-		// hash map of the best solution for each seen table
-		m map[semantics.TableSet]joinTree
-
-		highest semantics.TableSet
-	}
 )
 
-func makeDPTable() *dpTableT {
-	return &dpTableT{
-		m: map[semantics.TableSet]joinTree{},
-	}
-}
-
-func (dpt *dpTableT) add(tree joinTree) {
-	solved := tree.solves()
-	if dpt.highest < solved {
-		dpt.highest = solved
-	}
-	dpt.m[solved] = tree
-}
-
-func (dpt *dpTableT) planFor(id semantics.TableSet) joinTree {
-	return dpt.m[id]
-}
-
-func (dpt *dpTableT) bitSetsOfSize(wanted int) []joinTree {
-	var result []joinTree
-	for x := semantics.TableSet(1); x < dpt.highest; x++ {
-		if x.NumberOfTables() == wanted {
-			t, ok := dpt.m[x]
-			if ok {
-				result = append(result, t)
-			}
-		}
-	}
-	return result
-}
-
 func (rp *routePlan) solves() semantics.TableSet {
 	return rp.solved
 }
diff --git a/go/vt/vtgate/planbuilder/testdata/onecase.txt b/go/vt/vtgate/planbuilder/testdata/onecase.txt
index e819513f354..0ce1a45f0c9 100644
--- a/go/vt/vtgate/planbuilder/testdata/onecase.txt
+++ b/go/vt/vtgate/planbuilder/testdata/onecase.txt
@@ -1 +1,39 @@
 # Add your test case here for debugging and run go test -run=One.
+# ',' join
+"select music.col from user, music"
+{
+  "QueryType": "SELECT",
+  "Original": "select music.col from user, music",
+  "Instructions": {
+    "OperatorType": "Join",
+    "Variant": "Join",
+    "JoinColumnIndexes": "1",
+    "TableName": "user_music",
+    "Inputs": [
+      {
+        "OperatorType": "Route",
+        "Variant": "SelectScatter",
+        "Keyspace": {
+          "Name": "user",
+          "Sharded": true
+        },
+        "FieldQuery": "select 1 from user where 1 != 1",
+        "Query": "select 1 from user",
+        "Table": "user"
+      },
+      {
+        "OperatorType": "Route",
+        "Variant": "SelectScatter",
+        "Keyspace": {
+          "Name": "user",
+          "Sharded": true
+        },
+        "FieldQuery": "select music.col from music where 1 != 1",
+        "Query": "select music.col from music",
+        "Table": "music"
+      }
+    ]
+  }
+}
+{
+}