*: not load unnecessay data during the non-lite-init-stats (#53399)

close #53425

pkg/planner/cardinality/selectivity_test.go

@@ -1338,12 +1338,11 @@ func TestBuiltinInEstWithoutStats(t *testing.T) {
 		"└─Selection 0.08 cop[tikv]  in(test.t.a, 1, 2, 3, 4, 5, 6, 7, 8)",
 		"  └─TableFullScan 10.00 cop[tikv] table:t keep order:false, stats:pseudo",
 	))
-
 	h.Clear()
 	require.NoError(t, h.InitStats(is))
 	tk.MustQuery("explain format='brief' select * from t where a in (1, 2, 3, 4, 5, 6, 7, 8)").Check(testkit.Rows(
-		"TableReader 0.08 root  data:Selection",
-		"└─Selection 0.08 cop[tikv]  in(test.t.a, 1, 2, 3, 4, 5, 6, 7, 8)",
+		"TableReader 8.00 root  data:Selection",
+		"└─Selection 8.00 cop[tikv]  in(test.t.a, 1, 2, 3, 4, 5, 6, 7, 8)",
 		"  └─TableFullScan 10.00 cop[tikv] table:t keep order:false, stats:pseudo",
 	))
 }

pkg/statistics/handle/bootstrap.go

@@ -322,7 +322,10 @@ func (h *Handle) initStatsHistogramsByPaging(is infoschema.InfoSchema, cache sta
 		}
 	}()
 	sctx := se.(sessionctx.Context)
-	sql := "select HIGH_PRIORITY table_id, is_index, hist_id, distinct_count, version, null_count, cm_sketch, tot_col_size, stats_ver, correlation, flag, last_analyze_pos from mysql.stats_histograms where table_id >= %? and table_id < %?"
+	// Why do we need to add `is_index=1` in the SQL?
+	// because it is aligned to the `initStatsTopN` function, which only loads the topn of the index too.
+	// the other will be loaded by sync load.
+	sql := "select HIGH_PRIORITY table_id, is_index, hist_id, distinct_count, version, null_count, cm_sketch, tot_col_size, stats_ver, correlation, flag, last_analyze_pos from mysql.stats_histograms where table_id >= %? and table_id < %? and is_index=1"
 	rc, err := util.Exec(sctx, sql, task.StartTid, task.EndTid)
 	if err != nil {
 		return errors.Trace(err)

pkg/statistics/handle/handletest/statstest/stats_test.go

@@ -262,23 +262,12 @@ func TestInitStats(t *testing.T) {
 	h.Clear()
 	require.NoError(t, h.InitStats(is))
 	table0 := h.GetTableStats(tbl.Meta())
-	cols := table0.Columns
-	require.Equal(t, uint8(0x36), cols[1].LastAnalyzePos.GetBytes()[0])
-	require.Equal(t, uint8(0x37), cols[2].LastAnalyzePos.GetBytes()[0])
-	require.Equal(t, uint8(0x38), cols[3].LastAnalyzePos.GetBytes()[0])
+	idx := table0.Indices
+	require.Equal(t, uint8(0x3), idx[1].LastAnalyzePos.GetBytes()[0])
 	h.Clear()
 	require.NoError(t, h.Update(is))
 	// Index and pk are loaded.
 	needed := fmt.Sprintf(`Table:%v RealtimeCount:6
-column:1 ndv:6 totColSize:0
-num: 1 lower_bound: 1 upper_bound: 1 repeats: 1 ndv: 0
-num: 1 lower_bound: 2 upper_bound: 2 repeats: 1 ndv: 0
-num: 1 lower_bound: 3 upper_bound: 3 repeats: 1 ndv: 0
-num: 1 lower_bound: 4 upper_bound: 4 repeats: 1 ndv: 0
-num: 1 lower_bound: 5 upper_bound: 5 repeats: 1 ndv: 0
-num: 1 lower_bound: 6 upper_bound: 6 repeats: 1 ndv: 0
-column:2 ndv:6 totColSize:6
-column:3 ndv:6 totColSize:6
 index:1 ndv:6
 num: 1 lower_bound: 1 upper_bound: 1 repeats: 1 ndv: 0
 num: 1 lower_bound: 2 upper_bound: 2 repeats: 1 ndv: 0
@@ -328,26 +317,30 @@ func TestInitStats51358(t *testing.T) {
 }
 
 func TestInitStatsVer2(t *testing.T) {
-	restore := config.RestoreFunc()
-	defer restore()
-	config.UpdateGlobal(func(conf *config.Config) {
-		config.GetGlobalConfig().Performance.LiteInitStats = false
-		config.GetGlobalConfig().Performance.ConcurrentlyInitStats = false
-	})
-	initStatsVer2(t)
+	originValue := config.GetGlobalConfig().Performance.LiteInitStats
+	concurrentlyInitStatsValue := config.GetGlobalConfig().Performance.ConcurrentlyInitStats
+	defer func() {
+		config.GetGlobalConfig().Performance.LiteInitStats = originValue
+		config.GetGlobalConfig().Performance.ConcurrentlyInitStats = concurrentlyInitStatsValue
+	}()
+	config.GetGlobalConfig().Performance.LiteInitStats = false
+	config.GetGlobalConfig().Performance.ConcurrentlyInitStats = false
+	initStatsVer2(t, false)
 }
 
 func TestInitStatsVer2Concurrency(t *testing.T) {
-	restore := config.RestoreFunc()
-	defer restore()
-	config.UpdateGlobal(func(conf *config.Config) {
-		config.GetGlobalConfig().Performance.LiteInitStats = false
-		config.GetGlobalConfig().Performance.ConcurrentlyInitStats = true
-	})
-	initStatsVer2(t)
+	originValue := config.GetGlobalConfig().Performance.LiteInitStats
+	concurrentlyInitStatsValue := config.GetGlobalConfig().Performance.ConcurrentlyInitStats
+	defer func() {
+		config.GetGlobalConfig().Performance.LiteInitStats = originValue
+		config.GetGlobalConfig().Performance.ConcurrentlyInitStats = concurrentlyInitStatsValue
+	}()
+	config.GetGlobalConfig().Performance.LiteInitStats = false
+	config.GetGlobalConfig().Performance.ConcurrentlyInitStats = true
+	initStatsVer2(t, true)
 }
 
-func initStatsVer2(t *testing.T) {
+func initStatsVer2(t *testing.T, isConcurrency bool) {
 	store, dom := testkit.CreateMockStoreAndDomain(t)
 	tk := testkit.NewTestKit(t, store)
 	tk.MustExec("use test")
@@ -366,10 +359,19 @@ func initStatsVer2(t *testing.T) {
 	h.Clear()
 	require.NoError(t, h.InitStats(is))
 	table0 := h.GetTableStats(tbl.Meta())
-	cols := table0.Columns
-	require.Equal(t, uint8(0x33), cols[1].LastAnalyzePos.GetBytes()[0])
-	require.Equal(t, uint8(0x33), cols[2].LastAnalyzePos.GetBytes()[0])
-	require.Equal(t, uint8(0x33), cols[3].LastAnalyzePos.GetBytes()[0])
+	if isConcurrency {
+		idx := table0.Indices
+		require.Equal(t, uint8(0x3), idx[1].LastAnalyzePos.GetBytes()[0])
+		require.Equal(t, uint8(0x3), idx[2].LastAnalyzePos.GetBytes()[0])
+	} else {
+		cols := table0.Columns
+		require.Equal(t, uint8(0x33), cols[1].LastAnalyzePos.GetBytes()[0])
+		require.Equal(t, uint8(0x33), cols[2].LastAnalyzePos.GetBytes()[0])
+		require.Equal(t, uint8(0x33), cols[3].LastAnalyzePos.GetBytes()[0])
+		idx := table0.Indices
+		require.Equal(t, uint8(0x3), idx[1].LastAnalyzePos.GetBytes()[0])
+		require.Equal(t, uint8(0x3), idx[2].LastAnalyzePos.GetBytes()[0])
+	}
 	h.Clear()
 	require.NoError(t, h.InitStats(is))
 	table1 := h.GetTableStats(tbl.Meta())