Merge branch 'master' into stmt-cpu-dev

pingcap · Jun 2, 2021 · 027ef61 · 027ef61
2 parents 1f4d10b + c8c0dd0
commit 027ef61
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diff --git a/executor/stale_txn_test.go b/executor/stale_txn_test.go
@@ -451,6 +451,7 @@ func (s *testStaleTxnSerialSuite) TestSetTransactionReadOnlyAsOf(c *C) {
 		c.Assert(tk.Se.GetSessionVars().TxnReadTS.PeakTxnReadTS(), Equals, uint64(0))
 		tk.MustExec("begin")
 		c.Assert(tk.Se.GetSessionVars().TxnCtx.StartTS, Not(Equals), testcase.expectedTS)
+		tk.MustExec("commit")
 
 		failpoint.Disable("github.com/pingcap/tidb/expression/injectSafeTS")
 	}
@@ -682,6 +683,57 @@ func (s *testStaleTxnSuite) TestSpecialSQLInStalenessTxn(c *C) {
 	}
 }
 
+func (s *testStaleTxnSuite) TestAsOfTimestampCompatibility(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+	// For mocktikv, safe point is not initialized, we manually insert it for snapshot to use.
+	safePointName := "tikv_gc_safe_point"
+	safePointValue := "20160102-15:04:05 -0700"
+	safePointComment := "All versions after safe point can be accessed. (DO NOT EDIT)"
+	updateSafePoint := fmt.Sprintf(`INSERT INTO mysql.tidb VALUES ('%[1]s', '%[2]s', '%[3]s')
+	ON DUPLICATE KEY
+	UPDATE variable_value = '%[2]s', comment = '%[3]s'`, safePointName, safePointValue, safePointComment)
+	tk.MustExec(updateSafePoint)
+	tk.MustExec("use test")
+	tk.MustExec("create table t5(id int);")
+	time1 := time.Now()
+	testcases := []struct {
+		beginSQL string
+		sql      string
+	}{
+		{
+			beginSQL: fmt.Sprintf("START TRANSACTION READ ONLY AS OF TIMESTAMP '%s'", time1.Format("2006-1-2 15:04:05.000")),
+			sql:      fmt.Sprintf(`SET TRANSACTION READ ONLY AS OF TIMESTAMP '%s'`, time1.Format("2006-1-2 15:04:05.000")),
+		},
+		{
+			beginSQL: "begin",
+			sql:      fmt.Sprintf(`SET TRANSACTION READ ONLY AS OF TIMESTAMP '%s'`, time1.Format("2006-1-2 15:04:05.000")),
+		},
+		{
+			beginSQL: "start transaction",
+			sql:      fmt.Sprintf(`SET TRANSACTION READ ONLY AS OF TIMESTAMP '%s'`, time1.Format("2006-1-2 15:04:05.000")),
+		},
+		{
+			beginSQL: fmt.Sprintf("START TRANSACTION READ ONLY AS OF TIMESTAMP '%s'", time1.Format("2006-1-2 15:04:05.000")),
+			sql:      fmt.Sprintf("select * from t5 as of timestamp '%s'", time1.Format("2006-1-2 15:04:05.000")),
+		},
+		{
+			beginSQL: "begin",
+			sql:      fmt.Sprintf("select * from t5 as of timestamp '%s'", time1.Format("2006-1-2 15:04:05.000")),
+		},
+		{
+			beginSQL: "start transaction",
+			sql:      fmt.Sprintf("select * from t5 as of timestamp '%s'", time1.Format("2006-1-2 15:04:05.000")),
+		},
+	}
+	for _, testcase := range testcases {
+		tk.MustExec(testcase.beginSQL)
+		err := tk.ExecToErr(testcase.sql)
+		c.Assert(err, NotNil)
+		c.Assert(err.Error(), Matches, ".*as of timestamp can't be set in transaction.*")
+		tk.MustExec("commit")
+	}
+}
+
 func (s *testStaleTxnSuite) TestSetTransactionInfoSchema(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 	// For mocktikv, safe point is not initialized, we manually insert it for snapshot to use.

diff --git a/planner/core/preprocess.go b/planner/core/preprocess.go
@@ -1389,6 +1389,10 @@ func (p *preprocessor) handleAsOf(node *ast.AsOfClause) {
 	dom := domain.GetDomain(p.ctx)
 	ts := uint64(0)
 	if node != nil {
+		if p.ctx.GetSessionVars().InTxn() {
+			p.err = ErrAsOf.FastGenWithCause("as of timestamp can't be set in transaction.")
+			return
+		}
 		ts, p.err = calculateTsExpr(p.ctx, node)
 		if p.err != nil {
 			return

diff --git a/sessionctx/variable/sysvar.go b/sessionctx/variable/sysvar.go
@@ -829,6 +829,11 @@ var defaultSysVars = []*SysVar{
 	}},
 	{Scope: ScopeSession, Name: TiDBTxnReadTS, Value: "", Hidden: true, SetSession: func(s *SessionVars, val string) error {
 		return setTxnReadTS(s, val)
+	}, Validation: func(vars *SessionVars, normalizedValue string, originalValue string, scope ScopeFlag) (string, error) {
+		if vars.InTxn() {
+			return "", errors.New("as of timestamp can't be set in transaction")
+		}
+		return normalizedValue, nil
 	}},
 	{Scope: ScopeGlobal | ScopeSession, Name: TiDBAllowMPPExecution, Value: On, Type: TypeEnum, PossibleValues: []string{"OFF", "ON", "ENFORCE"}, SetSession: func(s *SessionVars, val string) error {
 		s.allowMPPExecution = val