planner,executor: relax the restrictions of trace format='row' (#10979)

executor/trace_test.go

@@ -39,6 +39,8 @@ func (s *testSuite1) TestTraceExec(c *C) {
 	// |   └─recordSet.Next        | 22:08:38.249340 | 155.317µs  |
 	// +---------------------------+-----------------+------------+
 	rows = tk.MustQuery("trace format='row' select * from trace where id = 0;").Rows()
+	c.Assert(len(rows) > 1, IsTrue)
 
+	rows = tk.MustQuery("trace format='row' delete from trace where id = 0").Rows()
 	c.Assert(len(rows) > 1, IsTrue)
 }

planner/core/planbuilder.go

@@ -1984,12 +1984,7 @@ func (b *PlanBuilder) buildDDL(node ast.DDLNode) (Plan, error) {
 // underlying query and then constructs a schema, which will be used to constructs
 // rows result.
 func (b *PlanBuilder) buildTrace(trace *ast.TraceStmt) (Plan, error) {
-	if _, ok := trace.Stmt.(*ast.SelectStmt); !ok && trace.Format == "row" {
-		return nil, errors.New("trace only supports select query when format is row")
-	}
-
 	p := &Trace{StmtNode: trace.Stmt, Format: trace.Format}
-
 	switch trace.Format {
 	case "row":
 		retFields := []string{"operation", "duration", "spanID"}