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Fix core at cost-based rewrite in temp table query

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This commit is contained in:
xianyu-w
2023-09-13 10:14:07 +00:00
committed by ob-robot
parent 9b0c76426b
commit e831a7f141
8 changed files with 255 additions and 178 deletions
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136
src/sql/optimizer/ob_optimizer_util.cpp
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@ -8923,7 +8923,7 @@ int ObOptimizerUtil::split_or_filter_into_subquery(const ObDMLStmt &parent_stmt,
check_match_index))) {
LOG_WARN("failed to split or fitler", K(ret));
}
for (int64_t i = 0; OB_SUCC(ret) && i < or_filter_params.count(); i ++) {
for (int64_t i = 0; i < or_filter_params.count(); i ++) {
if (OB_NOT_NULL(or_filter_params.at(i))) {
or_filter_params.at(i)->~ObIArray();
}
@ -9025,6 +9025,140 @@ int ObOptimizerUtil::split_or_filter_into_subquery(ObIArray<const ObDMLStmt *> &
return ret;
}
/**
* If every appearance of cte is accompanied by some filter,
* We can combine these filters to reduce the data materialized by cte.
* We try to push these filters to where condition.
* If all filters can be push to where condition, nonwhere_filter will be NULL.
* Otherwise, we might have both where_filter and nonwhere_filter.
* e.g.
* with cte as (select a,count(*) as cnt from t1 group by a)
* select * from cte where a = 1 and cnt = 1 union all select * from cte where a = 2 and cnt = 2;
* nonwhere_filter : (a = 1 and cnt = 1) or (a = 2 and cnt = 2)
* where_filter : (a = 1) or (a = 2)
*/
int ObOptimizerUtil::try_push_down_temp_table_filter(ObOptimizerContext &opt_ctx,
ObSqlTempTableInfo &info,
ObRawExpr *&nonwhere_filter,
ObRawExpr *&where_filter)
{
int ret = OB_SUCCESS;
bool have_filter = true;
nonwhere_filter = NULL;
where_filter = NULL;
ObSEArray<ObIArray<ObRawExpr *> *, 4> temp_table_filters;
ObSEArray<const ObDMLStmt *, 4> parent_stmts;
ObSEArray<const ObSelectStmt *, 4> subqueries;
ObSEArray<int64_t, 4> table_ids;
ObSelectStmt *temp_table_query = info.table_query_;
for (int64_t i = 0; OB_SUCC(ret) && have_filter && i < info.table_infos_.count(); ++i) {
TableItem *table = info.table_infos_.at(i).table_item_;
ObDMLStmt *stmt = info.table_infos_.at(i).upper_stmt_;
if (OB_ISNULL(table) || OB_ISNULL(stmt)) {
ret = OB_ERR_UNEXPECTED;
LOG_WARN("unexpected null", K(ret));
} else if (info.table_infos_.at(i).table_filters_.empty()) {
have_filter = false;
} else if (OB_FAIL(temp_table_filters.push_back(&info.table_infos_.at(i).table_filters_))) {
LOG_WARN("failed to push back", K(ret));
} else if (OB_FAIL(parent_stmts.push_back(stmt))) {
LOG_WARN("failed to push back", K(ret));
} else if (OB_FAIL(subqueries.push_back(temp_table_query))) {
LOG_WARN("failed to push back", K(ret));
} else if (OB_FAIL(table_ids.push_back(table->table_id_))) {
LOG_WARN("failed to push back", K(ret));
}
}
if (OB_SUCC(ret) && have_filter) {
OPT_TRACE("pushdown filter into temp table:", info.table_query_);
bool can_push_all = false;
if (OB_FAIL(ObOptimizerUtil::split_or_filter_into_subquery(parent_stmts,
subqueries,
table_ids,
temp_table_filters,
opt_ctx,
where_filter,
can_push_all,
/*check_match_index = */false))) {
LOG_WARN("failed to split filter", K(ret));
} else if (can_push_all) {
// do nothing
} else if (OB_FAIL(push_down_temp_table_filter(opt_ctx.get_expr_factory(), opt_ctx.get_session_info(),
info, nonwhere_filter))) {
LOG_WARN("failed to push down remain temp table filter", K(ret));
}
if (NULL != where_filter) {
OPT_TRACE("succeed to pushdown filter to where:", where_filter);
}
if (NULL != nonwhere_filter) {
OPT_TRACE("succeed to pushdown filter into the top of temp table:", nonwhere_filter);
}
}
return ret;
}
int ObOptimizerUtil::push_down_temp_table_filter(ObRawExprFactory &expr_factory,
ObSQLSessionInfo *session_info,
ObSqlTempTableInfo &info,
ObRawExpr *&temp_table_filter,
ObSelectStmt *temp_table_query)
{
int ret = OB_SUCCESS;
temp_table_filter = NULL;
ObSEArray<ObRawExpr *, 8> and_exprs;
ObRawExpr *or_expr = NULL;
bool have_temp_table_filter = true;
temp_table_query = (NULL == temp_table_query) ? info.table_query_ : temp_table_query;
if (OB_ISNULL(temp_table_query)) {
ret = OB_ERR_UNEXPECTED;
LOG_WARN("unexpect null param", K(info), K(ret));
}
for (int64_t i = 0; OB_SUCC(ret) && have_temp_table_filter && i < info.table_infos_.count(); ++i) {
have_temp_table_filter &= !info.table_infos_.at(i).table_filters_.empty();
}
for (int64_t i = 0; OB_SUCC(ret) && have_temp_table_filter && i < info.table_infos_.count(); ++i) {
ObDMLStmt *upper_stmt = info.table_infos_.at(i).upper_stmt_;
TableItem *table = info.table_infos_.at(i).table_item_;
ObIArray<ObRawExpr *> &table_filters = info.table_infos_.at(i).table_filters_;
ObSEArray<ObRawExpr *, 8> rename_exprs;
ObRawExpr *and_expr = NULL;
if (table_filters.empty() || OB_ISNULL(upper_stmt) ||
OB_ISNULL(table)) {
ret = OB_ERR_UNEXPECTED;
LOG_WARN("unexpect null table info", K(ret));
} else if (OB_FAIL(ObOptimizerUtil::rename_pushdown_filter(*upper_stmt,
*temp_table_query,
table->table_id_,
session_info,
expr_factory,
table_filters,
rename_exprs))) {
LOG_WARN("failed to rename push down preds", K(ret));
} else if (OB_FAIL(ObRawExprUtils::build_and_expr(expr_factory,
rename_exprs,
and_expr))) {
LOG_WARN("failed to build and expr", K(ret));
}
if (OB_SUCC(ret) && OB_FAIL(and_exprs.push_back(and_expr))) {
LOG_WARN("failed to push back expr", K(ret));
}
}
if (OB_FAIL(ret) || !have_temp_table_filter) {
} else if (OB_FAIL(ObRawExprUtils::build_or_exprs(expr_factory,
and_exprs,
or_expr))) {
LOG_WARN("failed to build or expr", K(ret));
} else if (OB_FAIL(or_expr->formalize(session_info))) {
LOG_WARN("failed to formalize expr", K(ret));
} else if (OB_FAIL(or_expr->pull_relation_id())) {
LOG_WARN("failed to pull relation id and levels", K(ret));
} else {
temp_table_filter = or_expr;
}
return ret;
}
bool ObOptimizerUtil::find_superset(const ObRelIds &rel_ids,
const ObIArray<ObRelIds> &single_table_ids)
{