statstics: avoid unnecessary try when to sync load (#56614)

pkg/statistics/handle/handle_hist.go

@@ -15,7 +15,7 @@
 package handle
 
 import (
-	"fmt"
+	stderrors "errors"
 	"math/rand"
 	"sync"
 	"time"
@@ -80,7 +80,6 @@ func (h *Handle) SendLoadRequests(sc *stmtctx.StatementContext, neededHistItems
 			}
 		}
 	})
-
 	if len(remainedItems) <= 0 {
 		return nil
 	}
@@ -327,6 +326,10 @@ func (h *Handle) handleOneItemTask(task *NeededItemTask) (err error) {
 	t := time.Now()
 	needUpdate := false
 	wrapper, err = h.readStatsForOneItem(sctx, item, wrapper)
+	if stderrors.Is(err, errGetHistMeta) {
+		metrics.ReadStatsHistogram.Observe(float64(time.Since(t).Milliseconds()))
+		return nil
+	}
 	if err != nil {
 		return err
 	}
@@ -346,6 +349,8 @@ func (h *Handle) handleOneItemTask(task *NeededItemTask) (err error) {
 	return nil
 }
 
+var errGetHistMeta = errors.New("fail to get stats version for this histogram")
+
 // readStatsForOneItem reads hist for one column/index, TODO load data via kv-get asynchronously
 func (h *Handle) readStatsForOneItem(sctx sessionctx.Context, item model.TableItemID, w *statsWrapper) (*statsWrapper, error) {
 	failpoint.Inject("mockReadStatsForOnePanic", nil)
@@ -424,9 +429,11 @@ func (h *Handle) readStatsForOneItem(sctx sessionctx.Context, item model.TableIt
 		return nil, errors.Trace(err)
 	}
 	if len(rows) == 0 {
-		logutil.BgLogger().Error("fail to get stats version for this histogram, normally this wouldn't happen, please check if this column or index has a histogram record in `mysql.stats_histogram`", zap.Int64("table_id", item.TableID),
-			zap.Int64("hist_id", item.ID), zap.Bool("is_index", item.IsIndex))
-		return nil, errors.Trace(fmt.Errorf("fail to get stats version for this histogram, normally this wouldn't happen, please check if this column or index has a histogram record in `mysql.stats_histogram`, table_id:%v, hist_id:%v, is_index:%v", item.TableID, item.ID, item.IsIndex))
+		logutil.BgLogger().Error("fail to get stats version for this histogram, normally this wouldn't happen, please check if this column or index has a histogram record in `mysql.stats_histogram`",
+			zap.Int64("table_id", item.TableID),
+			zap.Int64("hist_id", item.ID),
+			zap.Bool("is_index", item.IsIndex))
+		return nil, errGetHistMeta
 	}
 	statsVer := rows[0].GetInt64(0)
 	if item.IsIndex {

tests/integrationtest/r/planner/core/issuetest/planner_issue.result

@@ -592,3 +592,30 @@ _tidb_rowid
 1
 2
 3
+drop table if exists t1, t2, t3, t4;
+CREATE TABLE t1 (a int, b int, c int);
+CREATE TABLE t2 (a int, b int, c int);
+CREATE TABLE t3 (a int, b int, c int);
+CREATE TABLE t4 (a int, b int, c int);
+INSERT INTO t1 VALUES (1,3,0), (2,2,0), (3,2,0);
+INSERT INTO t2 VALUES (3,3,0), (4,2,0), (5,3,0);
+INSERT INTO t3 VALUES (1,2,0), (2,2,0);
+INSERT INTO t4 VALUES (3,2,0), (4,2,0);
+CREATE INDEX idx_b ON t2(b);
+SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
+FROM (t3,t4)
+LEFT JOIN
+(t1,t2)
+ON t3.a=1 AND t3.b=t2.b AND t2.b=t4.b order by 1, 2, 3, 4, 5;
+a	b	a	b	a	b
+NULL	NULL	2	2	3	2
+NULL	NULL	2	2	4	2
+4	2	1	2	3	2
+4	2	1	2	3	2
+4	2	1	2	3	2
+4	2	1	2	4	2
+4	2	1	2	4	2
+4	2	1	2	4	2
+show warnings;
+Level	Code	Message
+drop table if exists t1, t2, t3, t4;

tests/integrationtest/t/planner/core/issuetest/planner_issue.test

@@ -460,3 +460,21 @@ insert into t values (1, 10);
 insert into t values (2, 20);
 insert into t values (3, 30);
 select _tidb_rowid from t where id in (1, 2, 3);
+# TestIssue56472
+drop table if exists t1, t2, t3, t4;
+CREATE TABLE t1 (a int, b int, c int);
+CREATE TABLE t2 (a int, b int, c int);
+CREATE TABLE t3 (a int, b int, c int);
+CREATE TABLE t4 (a int, b int, c int);
+INSERT INTO t1 VALUES (1,3,0), (2,2,0), (3,2,0);
+INSERT INTO t2 VALUES (3,3,0), (4,2,0), (5,3,0);
+INSERT INTO t3 VALUES (1,2,0), (2,2,0);
+INSERT INTO t4 VALUES (3,2,0), (4,2,0);
+CREATE INDEX idx_b ON t2(b);
+SELECT t2.a,t2.b,t3.a,t3.b,t4.a,t4.b
+  FROM (t3,t4)
+       LEFT JOIN
+       (t1,t2)
+       ON t3.a=1 AND t3.b=t2.b AND t2.b=t4.b order by 1, 2, 3, 4, 5;
+show warnings;
+drop table if exists t1, t2, t3, t4;