address comment

Author: lzmhhh123

planner/core/logical_plan_builder.go

@@ -2536,9 +2536,7 @@ func (b *PlanBuilder) buildDataSource(ctx context.Context, tn *ast.TableName, as
 	if err != nil {
 		return nil, err
 	}
-	if dbName.L != mysql.SystemDB {
-		possiblePaths, err = b.filterPathByIsolationRead(possiblePaths)
-	}
+	possiblePaths, err = b.filterPathByIsolationRead(possiblePaths, dbName)
 	if err != nil {
 		return nil, err
 	}

planner/core/planbuilder.go

@@ -725,8 +725,11 @@ func (b *PlanBuilder) getPossibleAccessPaths(indexHints []*ast.IndexHint, tbl ta
 	return available, nil
 }
 
-func (b *PlanBuilder) filterPathByIsolationRead(paths []*util.AccessPath) ([]*util.AccessPath, error) {
+func (b *PlanBuilder) filterPathByIsolationRead(paths []*util.AccessPath, dbName model.CIStr) ([]*util.AccessPath, error) {
 	// TODO: filter paths with isolation read locations.
+	if dbName.L == mysql.SystemDB {
+		return paths, nil
+	}
 	isolationReadEngines := b.ctx.GetSessionVars().GetIsolationReadEngines()
 	availableEngine := map[kv.StoreType]struct{}{}
 	var availableEngineStr string