Files
oceanbase/src/sql/optimizer/ob_log_topk.cpp
2024-02-07 11:01:37 +00:00

166 lines
6.8 KiB
C++

/**
* Copyright (c) 2021 OceanBase
* OceanBase CE is licensed under Mulan PubL v2.
* You can use this software according to the terms and conditions of the Mulan PubL v2.
* You may obtain a copy of Mulan PubL v2 at:
* http://license.coscl.org.cn/MulanPubL-2.0
* THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
* EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
* MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
* See the Mulan PubL v2 for more details.
*/
#define USING_LOG_PREFIX SQL_OPT
#include "ob_log_topk.h"
#include "ob_log_group_by.h"
#include "ob_log_operator_factory.h"
#include "ob_log_sort.h"
#include "ob_log_table_scan.h"
#include "ob_optimizer_util.h"
#include "ob_opt_est_cost.h"
#include "sql/rewrite/ob_transform_utils.h"
using namespace oceanbase::sql;
using namespace oceanbase::common;
using namespace oceanbase::sql::log_op_def;
int ObLogTopk::set_topk_params(ObRawExpr *limit_count, ObRawExpr *limit_offset,
int64_t minimum_row_count, int64_t topk_precision)
{
int ret = OB_SUCCESS;
if (OB_ISNULL(limit_count)) {
ret = OB_INVALID_ARGUMENT;
LOG_WARN("limit_count is NULL", K(ret));
} else {
topk_limit_count_ = limit_count;
topk_limit_offset_ = limit_offset;
minimum_row_count_ = minimum_row_count;
topk_precision_ = topk_precision;
}
return ret;
}
int ObLogTopk::get_op_exprs(ObIArray<ObRawExpr*> &all_exprs)
{
int ret = OB_SUCCESS;
if (NULL != topk_limit_count_ && OB_FAIL(all_exprs.push_back(topk_limit_count_))) {
LOG_WARN("failed to push back exprs", K(ret));
} else if (NULL != topk_limit_offset_ && OB_FAIL(all_exprs.push_back(topk_limit_offset_))) {
LOG_WARN("failed to push back exprs", K(ret));
} else if (OB_FAIL(ObLogicalOperator::get_op_exprs(all_exprs))) {
LOG_WARN("failed to get exprs", K(ret));
} else { /*do nothing*/ }
return ret;
}
int ObLogTopk::est_width()
{
int ret = OB_SUCCESS;
double width = 0.0;
ObSEArray<ObRawExpr*, 16> output_exprs;
if (OB_ISNULL(get_plan())) {
ret = OB_ERR_UNEXPECTED;
LOG_WARN("invalid plan", K(ret));
} else if (OB_FAIL(get_topk_output_exprs(output_exprs))) {
LOG_WARN("failed to get topk output exprs", K(ret));
} else if (OB_FAIL(ObOptEstCost::estimate_width_for_exprs(get_plan()->get_basic_table_metas(),
get_plan()->get_selectivity_ctx(),
output_exprs,
width))) {
LOG_WARN("failed to estimate width for output topk exprs", K(ret));
} else {
set_width(width);
LOG_TRACE("est width for topk", K(output_exprs), K(width));
}
return ret;
}
int ObLogTopk::get_topk_output_exprs(ObIArray<ObRawExpr *> &output_exprs)
{
int ret = OB_SUCCESS;
ObLogPlan *plan = NULL;
ObSEArray<ObRawExpr*, 16> candi_exprs;
ObSEArray<ObRawExpr*, 16> extracted_col_aggr_winfunc_exprs;
if (OB_ISNULL(plan = get_plan())) {
ret = OB_ERR_UNEXPECTED;
LOG_WARN("invalid input", K(ret));
} else if (OB_FAIL(append_array_no_dup(candi_exprs, plan->get_select_item_exprs_for_width_est()))) {
LOG_WARN("failed to add into output exprs", K(ret));
} else if (OB_FAIL(ObRawExprUtils::extract_col_aggr_winfunc_exprs(candi_exprs,
extracted_col_aggr_winfunc_exprs))) {
} else if (OB_FAIL(append_array_no_dup(output_exprs, extracted_col_aggr_winfunc_exprs))) {
LOG_WARN("failed to add into output exprs", K(ret));
} else {/*do nothing*/}
return ret;
}
int ObLogTopk::est_cost()
{
int ret = OB_SUCCESS;
int64_t limit_count = 0;
int64_t offset_count = 0;
bool is_null_value = false;
int64_t parallel = 0.0;
ObLogicalOperator *child = NULL;
if (OB_ISNULL(child = get_child(first_child)) || OB_ISNULL(get_stmt()) ||
OB_ISNULL(get_plan())) {
ret = OB_ERR_UNEXPECTED;
LOG_WARN("get unexpected null", K(child), K(get_stmt()), K(get_plan()),K(ret));
} else if (OB_UNLIKELY((parallel = get_parallel()) < 1)) {
ret = OB_ERR_UNEXPECTED;
LOG_WARN("get unexpected parallel degree", K(ret));
} else if (OB_FAIL(ObTransformUtils::get_limit_value(topk_limit_count_,
get_plan()->get_optimizer_context().get_params(),
get_plan()->get_optimizer_context().get_exec_ctx(),
&get_plan()->get_optimizer_context().get_allocator(),
limit_count,
is_null_value))) {
LOG_WARN("get limit count num error", K(ret));
} else if (!is_null_value &&
OB_FAIL(ObTransformUtils::get_limit_value(topk_limit_offset_,
get_plan()->get_optimizer_context().get_params(),
get_plan()->get_optimizer_context().get_exec_ctx(),
&get_plan()->get_optimizer_context().get_allocator(),
offset_count,
is_null_value))) {
LOG_WARN("Get limit offset num error", K(ret));
} else {
limit_count = is_null_value ? 0 : limit_count + offset_count;
double topk_card = static_cast<double>(std::max(minimum_row_count_, limit_count));
double row_count = child->get_card() * static_cast<double>(topk_precision_) / 100.0;
topk_card = std::max(topk_card, row_count);
topk_card = std::min(topk_card, child->get_card());
ObOptimizerContext &opt_ctx = get_plan()->get_optimizer_context();
double op_cost = ObOptEstCost::cost_get_rows(topk_card / parallel,
opt_ctx);
set_card(topk_card);
set_op_cost(op_cost);
set_cost(child->get_cost() + op_cost);
}
return ret;
}
int ObLogTopk::get_plan_item_info(PlanText &plan_text,
ObSqlPlanItem &plan_item)
{
int ret = OB_SUCCESS;
if (OB_FAIL(ObLogicalOperator::get_plan_item_info(plan_text, plan_item))) {
LOG_WARN("failed to get plan item info", K(ret));
}
BEGIN_BUF_PRINT;
if (OB_FAIL(ret)) {
} else if (OB_FAIL(BUF_PRINTF("minimum_row_count:%ld top_precision:%ld ",
minimum_row_count_, topk_precision_))) {
LOG_WARN("BUF_PRINTF fails", K(ret));
} else {
ObRawExpr *limit = topk_limit_count_;
ObRawExpr *offset = topk_limit_offset_;
EXPLAIN_PRINT_EXPR(limit, type);
BUF_PRINTF(", ");
EXPLAIN_PRINT_EXPR(offset, type);
END_BUF_PRINT(plan_item.special_predicates_,
plan_item.special_predicates_len_);
}
return ret;
}