ks6.6: add a switch for alter user pessimistic (pingcap#285)

iosmanthus · Feb 28, 2023 · 57c7c5b · 57c7c5b
1 parent 0505fa1
commit 57c7c5b
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Showing 2 changed files with 14 additions and 2 deletions.
diff --git a/config/config.go b/config/config.go
@@ -280,6 +280,8 @@ type Config struct {
 
 	EnableRULimit bool `toml:"enable-ru-limit" json:"enable-ru-limit"`
 
+	EnableAlterUserPessimistic bool `toml:"enable-alter-user-pessimistic" json:"enable-alter-user-pessimistic"`
+
 	// The following items are deprecated. We need to keep them here temporarily
 	// to support the upgrade process. They can be removed in future.
 
@@ -1048,6 +1050,7 @@ var defaultConf = Config{
 	SkipGCDropTable:                      false,
 	SkipRedoDeleteRangeGC:                true,
 	EnableRULimit:                        false,
+	EnableAlterUserPessimistic:           false,
 	EnableGlobalKill:                     true,
 	TrxSummary:                           DefaultTrxSummary(),
 	DisaggregatedTiFlash:                 false,

diff --git a/executor/simple.go b/executor/simple.go
@@ -1725,8 +1725,17 @@ func (e *SimpleExec) executeAlterUser(ctx context.Context, s *ast.AlterUserStmt)
 	if err != nil {
 		return err
 	}
-	if _, err := sqlExecutor.ExecuteInternal(ctx, "BEGIN PESSIMISTIC"); err != nil {
-		return err
+
+	if config.GetGlobalConfig().EnableAlterUserPessimistic {
+		logutil.BgLogger().Info("execute `alter user` using PESSIMISTIC transaction")
+		if _, err := sqlExecutor.ExecuteInternal(ctx, "BEGIN PESSIMISTIC"); err != nil {
+			return err
+		}
+	} else {
+		logutil.BgLogger().Info("execute `alter user` using OPTIMISTIC transaction")
+		if _, err := sqlExecutor.ExecuteInternal(ctx, "BEGIN"); err != nil {
+			return err
+		}
 	}
 
 	for _, spec := range s.Specs {