Show filter condition (#87)

* Show Filter in EXPLAIN

* Fix value of LatencyTotal

* Add test case of filter

* Do go mod tidy

* Add comment

* Refactor isPredicate

* Use t.Fatal instead of t.Error

* Do gofmt

Co-authored-by: Yuki Furuyama <furuyama@google.com>

go.mod

@@ -6,6 +6,7 @@ require (
 	cloud.google.com/go v0.65.0
 	cloud.google.com/go/spanner v1.10.0
 	github.com/chzyer/readline v0.0.0-20180603132655-2972be24d48e
+	github.com/golang/protobuf v1.4.2
 	github.com/google/go-cmp v0.5.2
 	github.com/jessevdk/go-flags v1.4.0
 	github.com/mattn/go-runewidth v0.0.8 // indirect

query_plan.go

@@ -58,6 +58,14 @@ type executionStatsValue struct {
 	Total string `json:"total"`
 }
 
+func (v executionStatsValue) String() string {
+	if v.Unit == "" {
+		return v.Total
+	} else {
+		return fmt.Sprintf("%s %s", v.Total, v.Unit)
+	}
+}
+
 // queryPlanNodeWithStatsTyped is proto-free typed representation of QueryPlanNodeWithStats
 type queryPlanNodeWithStatsTyped struct {
 	ID             int32 `json:"id"`
@@ -112,6 +120,19 @@ type QueryPlanRow struct {
 	Predicates   []string
 }
 
+func isPredicate(planNodes []*pb.PlanNode, childLink *pb.PlanNode_ChildLink) bool {
+	// Known predicates are Condition(Filter) or Seek Condition/Residual Condition(FilterScan) or Split Range(Distributed Union).
+	// Agg is a Function but not a predicate.
+	child := planNodes[childLink.ChildIndex]
+	if child.DisplayName != "Function" {
+		return false
+	}
+	if strings.HasSuffix(childLink.GetType(), "Condition") || childLink.GetType() == "Split Range" {
+		return true
+	}
+	return false
+}
+
 func (n *Node) RenderTreeWithStats(planNodes []*pb.PlanNode) ([]QueryPlanRow, error) {
 	tree := treeprint.New()
 	renderTreeWithStats(tree, "", n)
@@ -142,11 +163,10 @@ func (n *Node) RenderTreeWithStats(planNodes []*pb.PlanNode) ([]QueryPlanRow, er
 
 		var predicates []string
 		for _, cl := range planNodes[planNode.ID].GetChildLinks() {
-			child := planNodes[cl.ChildIndex]
-			if child.DisplayName != "Function" || !(cl.GetType() == "Residual Condition" || cl.GetType() == "Seek Condition" || cl.GetType() == "Split Range") {
+			if !isPredicate(planNodes, cl) {
 				continue
 			}
-			predicates = append(predicates, fmt.Sprintf("%s: %s", cl.GetType(), child.GetShortRepresentation().GetDescription()))
+			predicates = append(predicates, fmt.Sprintf("%s: %s", cl.GetType(), planNodes[cl.ChildIndex].GetShortRepresentation().GetDescription()))
 		}
 
 		result = append(result, QueryPlanRow{
@@ -155,7 +175,7 @@ func (n *Node) RenderTreeWithStats(planNodes []*pb.PlanNode) ([]QueryPlanRow, er
 			Text:         branchText + text,
 			RowsTotal:    planNode.ExecutionStats.Rows.Total,
 			Execution:    planNode.ExecutionStats.ExecutionSummary.NumExecutions,
-			LatencyTotal: fmt.Sprintf("%s %s", planNode.ExecutionStats.Latency.Total, planNode.ExecutionStats.Latency.Unit),
+			LatencyTotal: planNode.ExecutionStats.Latency.String(),
 		})
 	}
 	return result, nil

query_plan_test.go

@@ -1,10 +1,12 @@
 package main
 
 import (
+	"io/ioutil"
 	"testing"
 
 	"github.com/google/go-cmp/cmp"
 	"google.golang.org/genproto/googleapis/spanner/v1"
+	"google.golang.org/protobuf/encoding/protojson"
 	"google.golang.org/protobuf/types/known/structpb"
 
 	pb "google.golang.org/genproto/googleapis/spanner/v1"
@@ -18,6 +20,77 @@ func mustNewStruct(m map[string]interface{}) *structpb.Struct {
 	}
 }
 
+func TestRenderTreeUsingTestdataPlans(t *testing.T) {
+	for _, test := range []struct {
+		title string
+		file  string
+		want  []QueryPlanRow
+	}{
+		{
+			// Original Query:
+			// SELECT s.LastName FROM (SELECT s.LastName FROM Singers AS s WHERE s.FirstName LIKE 'A%' LIMIT 3) s WHERE s.LastName LIKE 'Rich%';
+			title: "With Filter Operator",
+			file:  "testdata/plans/filter.input.json",
+			want: []QueryPlanRow{
+				{
+					ID:   0,
+					Text: "Serialize Result",
+				},
+				{
+					ID:         1,
+					Text:       "+- Filter",
+					Predicates: []string{"Condition: STARTS_WITH($LastName, 'Rich')"},
+				},
+				{
+					ID:   2,
+					Text: "   +- Global Limit",
+				},
+				{
+					ID:         3,
+					Text:       "      +- Distributed Union",
+					Predicates: []string{"Split Range: STARTS_WITH($FirstName, 'A')"},
+				},
+				{
+					ID:   4,
+					Text: "         +- Local Limit",
+				},
+				{
+					ID:   5,
+					Text: "            +- Local Distributed Union",
+				},
+				{
+					ID:         6,
+					Text:       "               +- FilterScan",
+					Predicates: []string{"Seek Condition: STARTS_WITH($FirstName, 'A')"},
+				},
+				{
+					ID:   7,
+					Text: "                  +- Index Scan (Index: SingersByFirstLastName)",
+				},
+			}},
+	} {
+		t.Run(test.title, func(t *testing.T) {
+			b, err := ioutil.ReadFile(test.file)
+			if err != nil {
+				t.Fatal(err)
+			}
+			var plan pb.QueryPlan
+			err = protojson.Unmarshal(b, &plan)
+			if err != nil {
+				t.Fatal(err)
+			}
+			tree := BuildQueryPlanTree(&plan, 0)
+			got, err := tree.RenderTreeWithStats(plan.GetPlanNodes())
+			if err != nil {
+				t.Errorf("error should be nil, but got = %v", err)
+			}
+			if !cmp.Equal(test.want, got) {
+				t.Errorf("node.RenderTreeWithStats() differ: %s", cmp.Diff(test.want, got))
+			}
+		})
+	}
+}
+
 func TestRenderTreeWithStats(t *testing.T) {
 	for _, test := range []struct {
 		title string