ddl, statistics: fix stats meta missing when creating many tables at …

…once (pingcap#38301)

close pingcap#36004, close pingcap#38189

statistics/handle/update.go

@@ -558,9 +558,13 @@ func (h *Handle) dumpTableStatCountToKV(id int64, delta variable.TableDelta) (up
  }
  } else {
  if delta.Delta < 0 {
- _, err = exec.ExecuteInternal(ctx, "update mysql.stats_meta set version = %?, count = count - %?, modify_count = modify_count + %? where table_id = %? and count >= %?", startTS, -delta.Delta, delta.Count, id, -delta.Delta)
+ // use INSERT INTO ... ON DUPLICATE KEY UPDATE here to fill missing stats_meta.
+ _, err = exec.ExecuteInternal(ctx, "insert into mysql.stats_meta (version, table_id, modify_count, count) values (%?, %?, %?, 0) on duplicate key "+
+ "update version = values(version), modify_count = modify_count + values(modify_count), count = if(count > %?, count - %?, 0)", startTS, id, delta.Count, -delta.Delta, -delta.Delta)
  } else {
- _, err = exec.ExecuteInternal(ctx, "update mysql.stats_meta set version = %?, count = count + %?, modify_count = modify_count + %? where table_id = %?", startTS, delta.Delta, delta.Count, id)
+ // use INSERT INTO ... ON DUPLICATE KEY UPDATE here to fill missing stats_meta.
+ _, err = exec.ExecuteInternal(ctx, "insert into mysql.stats_meta (version, table_id, modify_count, count) values (%?, %?, %?, %?) on duplicate key "+
+ "update version = values(version), modify_count = modify_count + values(modify_count), count = count + values(count)", startTS, id, delta.Count, delta.Delta)
  }
  }
  statsVer = startTS

statistics/handle/update_test.go

@@ -1151,13 +1151,15 @@ func TestOutOfOrderUpdate(t *testing.T) {
 
  testKit.MustExec("delete from t")
  require.NoError(t, h.DumpStatsDeltaToKV(handle.DumpAll))
- testKit.MustQuery("select count from mysql.stats_meta").Check(testkit.Rows("1"))
+ // If count < -Delta, then update count to 0.
+ // Check https://github.com/pingcap/tidb/pull/38301#discussion_r1094050951 for details.
+ testKit.MustQuery(fmt.Sprintf("select count from mysql.stats_meta where table_id = %d", tableInfo.ID)).Check(testkit.Rows("0"))
 
  // Now another tidb has updated the delta info.
  testKit.MustExec(fmt.Sprintf("update mysql.stats_meta set count = 3 where table_id = %d", tableInfo.ID))
 
  require.NoError(t, h.DumpStatsDeltaToKV(handle.DumpAll))
- testKit.MustQuery("select count from mysql.stats_meta").Check(testkit.Rows("0"))
+ testKit.MustQuery(fmt.Sprintf("select count from mysql.stats_meta where table_id = %d", tableInfo.ID)).Check(testkit.Rows("3"))
 }
 
 func TestUpdateStatsByLocalFeedback(t *testing.T) {
@@ -2620,3 +2622,54 @@ func TestStatsLockForDelta(t *testing.T) {
  stats1 = h.GetTableStats(tableInfo1)
  require.Equal(t, int64(30), stats1.Count)
 }
+
+func TestFillMissingStatsMeta(t *testing.T) {
+ store, dom := testkit.CreateMockStoreAndDomain(t)
+ tk := testkit.NewTestKit(t, store)
+ tk.MustExec("use test")
+ tk.MustExec("create table t1 (a int, b int)")
+ tk.MustExec("create table t2 (a int, b int) partition by range (a) (partition p0 values less than (10), partition p1 values less than (maxvalue))")
+
+ tk.MustQuery("select * from mysql.stats_meta").Check(testkit.Rows())
+
+ is := dom.InfoSchema()
+ tbl1, err := is.TableByName(model.NewCIStr("test"), model.NewCIStr("t1"))
+ require.NoError(t, err)
+ tbl1ID := tbl1.Meta().ID
+ tbl2, err := is.TableByName(model.NewCIStr("test"), model.NewCIStr("t2"))
+ require.NoError(t, err)
+ tbl2Info := tbl2.Meta()
+ tbl2ID := tbl2Info.ID
+ require.Len(t, tbl2Info.Partition.Definitions, 2)
+ p0ID := tbl2Info.Partition.Definitions[0].ID
+ p1ID := tbl2Info.Partition.Definitions[1].ID
+ h := dom.StatsHandle()
+
+ checkStatsMeta := func(id int64, expectedModifyCount, expectedCount string) int64 {
+ rows := tk.MustQuery(fmt.Sprintf("select version, modify_count, count from mysql.stats_meta where table_id = %v", id)).Rows()
+ require.Len(t, rows, 1)
+ ver, err := strconv.ParseInt(rows[0][0].(string), 10, 64)
+ require.NoError(t, err)
+ require.Equal(t, expectedModifyCount, rows[0][1])
+ require.Equal(t, expectedCount, rows[0][2])
+ return ver
+ }
+
+ tk.MustExec("insert into t1 values (1, 2), (3, 4)")
+ require.NoError(t, h.DumpStatsDeltaToKV(handle.DumpAll))
+ ver1 := checkStatsMeta(tbl1ID, "2", "2")
+ tk.MustExec("delete from t1 where a = 1")
+ require.NoError(t, h.DumpStatsDeltaToKV(handle.DumpAll))
+ ver2 := checkStatsMeta(tbl1ID, "3", "1")
+ require.Greater(t, ver2, ver1)
+
+ tk.MustExec("insert into t2 values (1, 2), (3, 4)")
+ require.NoError(t, h.DumpStatsDeltaToKV(handle.DumpAll))
+ checkStatsMeta(p0ID, "2", "2")
+ globalVer1 := checkStatsMeta(tbl2ID, "2", "2")
+ tk.MustExec("insert into t2 values (11, 12)")
+ require.NoError(t, h.DumpStatsDeltaToKV(handle.DumpAll))
+ checkStatsMeta(p1ID, "1", "1")
+ globalVer2 := checkStatsMeta(tbl2ID, "3", "3")
+ require.Greater(t, globalVer2, globalVer1)
+}