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update rewrite rules

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* adjust re est cost for nestloop semi/anti join

* add threshold for cost base transform
This commit is contained in:
zs
2021-06-16 11:36:24 +08:00
committed by MizuhaHimuraki
parent cbeee6568e
commit 03001c1fe3
6 changed files with 70 additions and 84 deletions
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15
src/sql/optimizer/ob_join_order.cpp
View File

@ -3515,12 +3515,10 @@ int JoinPath::re_est_cost(sql::Path* path, double need_row_count, double& cost)
if (OB_ISNULL(path)) {
ret = OB_ERR_UNEXPECTED;
LOG_WARN("unexpect null path", K(ret));
} else if (ACCESS == path->path_type_ &&
OB_FAIL(re_est_access_cost(static_cast<AccessPath*>(path), need_row_count, cost))) {
LOG_WARN("failed to est access cost", K(ret));
} else if (SUBQUERY == path->path_type_ &&
OB_FAIL(re_est_subquery_cost(static_cast<SubQueryPath*>(path), need_row_count, cost))) {
LOG_WARN("failed to est subquery cost", K(ret));
} else if (ACCESS == path->path_type_) {
ret = re_est_access_cost(static_cast<AccessPath*>(path), need_row_count, cost);
} else if (SUBQUERY == path->path_type_) {
ret = re_est_subquery_cost(static_cast<SubQueryPath*>(path), need_row_count, cost);
} else {
cost = path->cost_;
}
@ -3570,11 +3568,6 @@ int JoinPath::re_est_access_cost(AccessPath* path, double need_row_count, double
cost,
index_back_cost))) {
LOG_WARN("failed to estimate cost", K(ret));
} else {
path->cost_ = cost;
path->op_cost_ = cost;
path->inner_row_count_ = need_row_count;
path->output_row_count_ = need_row_count;
}
} else {
cost = path->cost_;

2
src/sql/rewrite/ob_transform_rule.cpp
View File

@ -167,7 +167,7 @@ int ObTransformRule::accept_transform(
LOG_WARN("failed to evaluate cost for the origin stmt", K(ret));
}
if (OB_SUCC(ret)) {
if (trans_stmt_cost < stmt_cost_) {
if (trans_stmt_cost < stmt_cost_ * COST_BASE_TRANSFORM_THRESHOLD) {
LOG_TRACE("accept transform because the cost is decreased", K_(stmt_cost), K(trans_stmt_cost));
stmt = trans_stmt;
stmt_cost_ = trans_stmt_cost;

1
src/sql/rewrite/ob_transform_rule.h
View File

@ -129,6 +129,7 @@ struct ObParentDMLStmt {
class ObTransformRule {
public:
static constexpr const double COST_BASE_TRANSFORM_THRESHOLD = 0.999;
static const int64_t TRANSFORMER_DEFAULT_MAX_RECURSIVE_LEVEL = 150;
static const uint64_t ALL_TRANSFORM_RULES = TRANSFORM_TYPE_COUNT_PLUS_ONE - 1;
static const uint64_t ALL_HEURISTICS_RULES = SIMPLIFY | ANYALL | AGGR | ELIMINATE_OJ | VIEW_MERGE | WHERE_SQ_PULL_UP |