revert 'fix avg scale is not compat with MySQL'

src/sql/dtl/ob_dtl_flow_control.cpp

@@ -158,7 +158,7 @@ int ObDtlFlowControl::unregister_all_channel()
     }
   }
   if (is_receive() && (0 != get_blocked_cnt() || 0 != get_total_buffer_cnt() || 0 != get_used())) {
-    LOG_ERROR("unexpected dfc status", K(chans_.count()), K(ret), K(get_blocked_cnt()), K(get_total_buffer_cnt()), K(get_used()), K(get_accumulated_blocked_cnt()));
+    LOG_WARN("unexpected dfc status", K(chans_.count()), K(ret), K(get_blocked_cnt()), K(get_total_buffer_cnt()), K(get_used()), K(get_accumulated_blocked_cnt()));
   }
   LOG_TRACE("unregister all channel", K(chans_.count()), K(ret), K(get_blocked_cnt()), K(get_total_buffer_cnt()), K(get_used()), K(get_accumulated_blocked_cnt()));
   return ret;

src/sql/engine/expr/ob_expr_div.cpp

@@ -609,16 +609,11 @@ struct ObNumberDivFunc
             //          const int64_t new_scale2 = ROUND_UP(scale2);
             //          const int64_t calc_scale = ROUND_UP(new_scale1 + new_scale2 + div_pi);
             const int64_t calc_scale = expr.div_calc_scale_;
-            if (calc_scale > 0) {
-              if (T_OP_AGG_DIV == expr.type_) {
-                if (OB_FAIL(result_num.round(expr.datum_meta_.scale_))) {
-                  LOG_WARN("failed to round result number", K(ret), K(result_num), K(calc_scale));
-                }
-              } else if (OB_FAIL(result_num.trunc(calc_scale))) {
-                LOG_WARN("failed to round result number", K(ret), K(result_num), K(calc_scale));
-              }
-            }
-            if (OB_SUCC(ret)) {
+            if (calc_scale > 0 && OB_FAIL(result_num.trunc(calc_scale))) {
+              //calc_scale is calc_scale ,not res_scale.
+              //trunc with calc_scale and round with res_scale
+              LOG_WARN("failed to trunc result number", K(ret), K(result_num), K(calc_scale));
+            } else {
               res.set_number(result_num);
             }
             LOG_DEBUG("finish div", K(ret), K(calc_scale),