From 67b143d4a8ab857d3f90ca1e8fd69c5d1949e6a0 Mon Sep 17 00:00:00 2001
From: Ti Chi Robot <ti-community-prow-bot@tidb.io>
Date: Tue, 5 Dec 2023 17:58:19 +0800
Subject: [PATCH] statstics: remove useless cache (#48650) (#48651)

ref pingcap/tidb#47275
---
 pkg/executor/BUILD.bazel                      |  1 -
 pkg/executor/analyze_global_stats.go          | 20 +++----------------
 .../handle/globalstats/global_stats.go        |  1 -
 pkg/statistics/handle/util/interfaces.go      |  1 -
 4 files changed, 3 insertions(+), 20 deletions(-)

diff --git a/pkg/executor/BUILD.bazel b/pkg/executor/BUILD.bazel
index 316d0f5f3b3c9..4a6f6d13f9fd4 100644
--- a/pkg/executor/BUILD.bazel
+++ b/pkg/executor/BUILD.bazel
@@ -274,7 +274,6 @@ go_library(
         "@org_golang_google_grpc//credentials",
         "@org_golang_google_grpc//credentials/insecure",
         "@org_golang_google_grpc//status",
-        "@org_golang_x_exp//maps",
         "@org_golang_x_sync//errgroup",
         "@org_uber_go_atomic//:atomic",
         "@org_uber_go_zap//:zap",
diff --git a/pkg/executor/analyze_global_stats.go b/pkg/executor/analyze_global_stats.go
index 3aed3bb4f986a..59d01638524be 100644
--- a/pkg/executor/analyze_global_stats.go
+++ b/pkg/executor/analyze_global_stats.go
@@ -26,7 +26,6 @@ import (
 	"github.com/pingcap/tidb/pkg/types"
 	"github.com/pingcap/tidb/pkg/util/logutil"
 	"go.uber.org/zap"
-	"golang.org/x/exp/maps"
 )
 
 type globalStatsKey struct {
@@ -48,17 +47,15 @@ type globalStatsInfo struct {
 type globalStatsMap map[globalStatsKey]globalStatsInfo
 
 func (e *AnalyzeExec) handleGlobalStats(ctx context.Context, globalStatsMap globalStatsMap) error {
-	globalStatsTableIDs := make(map[int64]int, len(globalStatsMap))
+	globalStatsTableIDs := make(map[int64]struct{}, len(globalStatsMap))
 	for globalStatsID := range globalStatsMap {
-		globalStatsTableIDs[globalStatsID.tableID]++
+		globalStatsTableIDs[globalStatsID.tableID] = struct{}{}
 	}
 
 	statsHandle := domain.GetDomain(e.Ctx()).StatsHandle()
 	tableIDs := make(map[int64]struct{}, len(globalStatsTableIDs))
-	tableAllPartitionStats := make(map[int64]*statistics.Table)
-	for tableID, count := range globalStatsTableIDs {
+	for tableID := range globalStatsTableIDs {
 		tableIDs[tableID] = struct{}{}
-		maps.Clear(tableAllPartitionStats)
 		for globalStatsID, info := range globalStatsMap {
 			if globalStatsID.tableID != tableID {
 				continue
@@ -78,20 +75,12 @@ func (e *AnalyzeExec) handleGlobalStats(ctx context.Context, globalStatsMap glob
 						globalOpts = v2Options.FilledOpts
 					}
 				}
-				var cache map[int64]*statistics.Table
-				if count > 1 {
-					cache = tableAllPartitionStats
-				} else {
-					cache = nil
-				}
-
 				globalStatsI, err := statsHandle.MergePartitionStats2GlobalStatsByTableID(
 					e.Ctx(),
 					globalOpts, e.Ctx().GetInfoSchema().(infoschema.InfoSchema),
 					globalStatsID.tableID,
 					info.isIndex == 1,
 					info.histIDs,
-					cache,
 				)
 				if err != nil {
 					logutil.BgLogger().Warn("merge global stats failed",
@@ -132,9 +121,6 @@ func (e *AnalyzeExec) handleGlobalStats(ctx context.Context, globalStatsMap glob
 			}()
 			FinishAnalyzeMergeJob(e.Ctx(), job, mergeStatsErr)
 		}
-		for _, value := range tableAllPartitionStats {
-			value.ReleaseAndPutToPool()
-		}
 	}
 
 	for tableID := range tableIDs {
diff --git a/pkg/statistics/handle/globalstats/global_stats.go b/pkg/statistics/handle/globalstats/global_stats.go
index d5abb16a03ee1..c769daff4f293 100644
--- a/pkg/statistics/handle/globalstats/global_stats.go
+++ b/pkg/statistics/handle/globalstats/global_stats.go
@@ -52,7 +52,6 @@ func (sg *statsGlobalImpl) MergePartitionStats2GlobalStatsByTableID(sc sessionct
 	physicalID int64,
 	isIndex bool,
 	histIDs []int64,
-	_ map[int64]*statistics.Table,
 ) (globalStats interface{}, err error) {
 	return MergePartitionStats2GlobalStatsByTableID(sc, sg.statsHandler, opts, is, physicalID, isIndex, histIDs)
 }
diff --git a/pkg/statistics/handle/util/interfaces.go b/pkg/statistics/handle/util/interfaces.go
index 14c85f4ed092d..6086a330a207e 100644
--- a/pkg/statistics/handle/util/interfaces.go
+++ b/pkg/statistics/handle/util/interfaces.go
@@ -305,7 +305,6 @@ type StatsGlobal interface {
 		physicalID int64,
 		isIndex bool,
 		histIDs []int64,
-		_ map[int64]*statistics.Table,
 	) (globalStats interface{}, err error)
 
 	// UpdateGlobalStats will trigger the merge of global-stats when we drop table partition