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disable join elimination for delete/update when the eliminated table is also a deleted/updated table

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This commit is contained in:
zz0
2021-10-19 21:03:41 +08:00
committed by wangzelin.wzl
parent a809ae9f36
commit 0d3a41c33d
2 changed files with 60 additions and 5 deletions
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38
src/sql/rewrite/ob_transform_join_elimination.cpp
View File

@ -60,7 +60,29 @@ int ObTransformJoinElimination::transform_one_stmt(
return ret;
}
int ObTransformJoinElimination::eliminate_join_self_foreign_key(ObDMLStmt* stmt, bool& trans_happened)
int ObTransformJoinElimination::check_table_can_be_eliminated(const ObDMLStmt *stmt, uint64_t table_id, bool &is_valid)
{
int ret = OB_SUCCESS;
is_valid = true;
if (OB_ISNULL(stmt)) {
ret = OB_ERR_UNEXPECTED;
LOG_WARN("get unexpected null stmt", K(ret));
} else if (stmt->is_delete_stmt() || stmt->is_update_stmt()) {
const ObDelUpdStmt *del_up_stmt = static_cast<const ObDelUpdStmt *>(stmt);
for (uint64_t i = 0; OB_SUCC(ret) && i < del_up_stmt->get_all_table_columns().count(); ++i) {
const TableColumns &tab_cols = del_up_stmt->get_all_table_columns().at(i);
const IndexDMLInfo &index_info = tab_cols.index_dml_infos_.at(0);
if (index_info.table_id_ == table_id) {
is_valid = false;
}
}
} else {
// TODO: add more cases if necessary
}
return ret;
}
int ObTransformJoinElimination::eliminate_join_self_foreign_key(ObDMLStmt *stmt, bool &trans_happened)
{
int ret = OB_SUCCESS;
bool from_happedend = false;
@ -1707,6 +1729,7 @@ int ObTransformJoinElimination::eliminate_candi_tables(ObDMLStmt* stmt, ObIArray
trans_happened = false;
EqualSets* equal_sets = &ctx_->equal_sets_;
ObArenaAllocator allocator;
bool is_valid = true;
if (conds.empty()) {
/*do nothing*/
} else if (OB_FAIL(ObEqualAnalysis::compute_equal_set(&allocator, conds, *equal_sets))) {
@ -1721,6 +1744,10 @@ int ObTransformJoinElimination::eliminate_candi_tables(ObDMLStmt* stmt, ObIArray
for (int64_t j = 0; OB_SUCC(ret) && j < candi_tables.count(); ++j) {
if (i == j || removed_items.has_member(j)) {
/*do nothing*/
} else if (OB_FAIL(check_table_can_be_eliminated(stmt, candi_tables.at(j)->table_id_, is_valid))) {
LOG_WARN("check table can be eliminated failed", K(ret));
} else if (!is_valid) {
// do nothing
} else if (OB_FAIL(do_join_elimination_self_key(
stmt, candi_tables.at(i), candi_tables.at(j), is_happened, equal_sets))) {
LOG_WARN("failed to eliminate self key join in base table", K(ret));
@ -1734,8 +1761,13 @@ int ObTransformJoinElimination::eliminate_candi_tables(ObDMLStmt* stmt, ObIArray
}
is_happened = false;
for (int64_t j = 0; OB_SUCC(ret) && !is_happened && j < child_candi_tables.count(); ++j) {
if (OB_FAIL(do_join_elimination_self_key(
stmt, child_candi_tables.at(j), candi_tables.at(i), is_happened, equal_sets))) {
is_valid = true;
if (OB_FAIL(check_table_can_be_eliminated(stmt, candi_tables.at(i)->table_id_, is_valid))) {
LOG_WARN("check table can be eliminated failed", K(ret));
} else if (!is_valid) {
// do nothing
} else if (OB_FAIL(do_join_elimination_self_key(
stmt, child_candi_tables.at(j), candi_tables.at(i), is_happened, equal_sets))) {
LOG_WARN("failed to do join elimination erlf key", K(ret));
} else if (!is_happened) {
/*do nothing*/

27
src/sql/rewrite/ob_transform_join_elimination.h
View File

@ -55,9 +55,32 @@ public:
common::ObIArray<ObParentDMLStmt>& parent_stmts, ObDMLStmt*& stmt, bool& trans_happened) override;
private:
int eliminate_join_self_foreign_key(ObDMLStmt* stmt, bool& trans_happened);
/**
* @brief
* check if a table can be eliminated
* delete p1, p2 FROM t1 as p1, t1 as p2 where p1.a=p2.a;
* p2 can not be eliminateed since it is going to be updated/deleted
* @param stmt
* @param table_id
* @param is_valid
* @return int
*/
int check_table_can_be_eliminated(const ObDMLStmt *stmt, uint64_t table_id, bool &is_valid);
int eliminate_join_in_from_base_table(ObDMLStmt* stmt, bool& trans_happened);
/**
* @brief eliminate_join_self_key
* cases that can be eliminated for self key join：
* basic_table or generate_table within STMT FROM ITEMS
* basic_table or generate_table within SEMI ITEMS
* inner join tables within SEMI ITEMS or STMT ITEMS
*/
int eliminate_join_self_foreign_key(ObDMLStmt *stmt, bool &trans_happened);
/**
* @brief eliminate_SKJ_in_from_base_table
* eliminate self key loseless join existed in basic table or generate table within STMT FROM ITEMS
*/
int eliminate_join_in_from_base_table(ObDMLStmt *stmt, bool &trans_happened);
int eliminate_join_in_from_item(
ObDMLStmt* stmt, const ObIArray<FromItem>& from_items, SemiInfo* semi_info, bool& trans_happened);