revision-id: 81787adb79a71e47a506a3c780019fdbba3aafe2 (mariadb-10.4.11-422-g81787adb79a) parent(s): 5cac06a04a468b421e39fff3daab7f93c28063f5 author: Sergei Petrunia committer: Sergei Petrunia timestamp: 2021-01-27 14:32:09 +0300 message: Address review input, part #1 (obvious fixes) --- sql/opt_range.cc | 40 ++++++++++++++++++++++++++++------------ 1 file changed, 28 insertions(+), 12 deletions(-) diff --git a/sql/opt_range.cc b/sql/opt_range.cc index df9d6ba68e0..48ac16e1de9 100644 --- a/sql/opt_range.cc +++ b/sql/opt_range.cc @@ -9769,8 +9769,8 @@ and_all_keys(RANGE_OPT_PARAM *param, SEL_ARG *key1, SEL_ARG *key2, if (!key1) return &null_element; // Impossible ranges key1->use_count++; - key1->max_part_no= MY_MAX(key2->max_part_no, key2->part+1); key1->weight= new_weight; + key1->max_part_no= MY_MAX(key2->max_part_no, key2->part+1); return key1; } @@ -9840,7 +9840,7 @@ key_and(RANGE_OPT_PARAM *param, SEL_ARG *key1, SEL_ARG *key2, uint clone_flag) key1->next_key_part=key_and(param, key1->next_key_part, key2->next_key_part, clone_flag); - key1->weight = 1 + (key1->next_key_part? key1->next_key_part->weight : 0); + key1->weight= 1 + (key1->next_key_part? key1->next_key_part->weight : 0); if (key1->next_key_part && key1->next_key_part->type == SEL_ARG::IMPOSSIBLE) @@ -9893,6 +9893,11 @@ key_and(RANGE_OPT_PARAM *param, SEL_ARG *key1, SEL_ARG *key2, uint clone_flag) if (!new_arg) return &null_element; // End of memory new_arg->next_key_part=next; + /* + We are going to add the 'new_arg' range to the new_tree. + the new_arg on its own has weight=1. + if it has non-null new_arg->next_key_part (=next), add its weight, too. + */ new_weight += 1 + (next? next->weight: 0); if (!new_tree) { @@ -9948,7 +9953,7 @@ uint SEL_ARG::verify_weight() { for (SEL_ARG *arg= first_arg; arg; arg= arg->next) { - computed_weight += 1; + computed_weight++; if (arg->next_key_part) computed_weight+= arg->next_key_part->verify_weight(); } @@ -9966,6 +9971,7 @@ uint SEL_ARG::verify_weight() { sql_print_error("SEL_ARG weight mismatch: computed %u have %u\n", computed_weight, weight); + DBUG_ASSERT(computed_weight == weight); // Fail an assertion } return computed_weight; } @@ -10715,7 +10721,7 @@ uint SEL_ARG::get_max_key_part() const if (cur->next_key_part) { uint mp= cur->next_key_part->get_max_key_part(); - max_part = MY_MAX(part, mp); + max_part= MY_MAX(part, mp); } } return max_part; @@ -10746,10 +10752,9 @@ void prune_sel_arg_graph(SEL_ARG *sel_arg, uint max_part) } else { - uint old_weight = cur->next_key_part->weight; + uint old_weight= cur->next_key_part->weight; prune_sel_arg_graph(cur->next_key_part, max_part); - old_weight -= cur->next_key_part->weight; - sel_arg->weight -= old_weight; + sel_arg->weight -= (old_weight - cur->next_key_part->weight); } } } @@ -10791,12 +10796,17 @@ SEL_ARG *enforce_sel_arg_weight_limit(RANGE_OPT_PARAM *param, uint keyno, while (1) { - if (sel_arg->weight <= param->thd->variables.optimizer_max_sel_arg_weight) + if (likely(sel_arg->weight <= param->thd->variables. + optimizer_max_sel_arg_weight)) break; uint max_part= sel_arg->get_max_key_part(); if (max_part == sel_arg->part) { + /* + We don't return NULL right away as we want to have the information + about the changed tree in the optimizer trace. + */ sel_arg= NULL; break; } @@ -10950,11 +10960,17 @@ SEL_ARG::tree_delete(SEL_ARG *key) root=this; this->parent= 0; - // Compute the weight the tree will have after the element is removed - // We remove the element itself (weight=1) - // and the sub-graph connected to its next_key_part. + /* + Compute the weight the tree will have after the element is removed. + We remove the element itself (weight=1) + and the sub-graph connected to its next_key_part. + */ uint new_weight= root->weight - (1 + (key->next_key_part? key->next_key_part->weight : 0)); + + DBUG_ASSERT(root->weight > (1 + (key->next_key_part ? + key->next_key_part->weight : 0)); + /* Unlink from list */ if (key->prev) key->prev->next=key->next; @@ -11006,7 +11022,7 @@ SEL_ARG::tree_delete(SEL_ARG *key) test_rb_tree(root,root->parent); root->use_count=this->use_count; // Fix root counters - root->weight = new_weight; + root->weight= new_weight; root->elements=this->elements-1; root->maybe_flag=this->maybe_flag; DBUG_RETURN(root);