[CP] [CP] fix table scan range cost bug

src/sql/optimizer/ob_join_order.cpp

@@ -73,6 +73,7 @@ int ObJoinOrder::fill_query_range_info(const QueryRangeInfo &range_info,
   const ObQueryRangeArray &ss_ranges = range_info.get_ss_ranges();
   est_cost_info.ranges_.reset();
   est_cost_info.ss_ranges_.reset();
+  est_cost_info.at_most_one_range_ = false;
   // maintain query range info
   for(int64_t i = 0; OB_SUCC(ret) && i < ranges.count(); ++i) {
     if (OB_ISNULL(ranges.at(i))) {
@@ -90,6 +91,37 @@ int ObJoinOrder::fill_query_range_info(const QueryRangeInfo &range_info,
       LOG_WARN("failed to add range", K(ret));
     } else { /*do nothing*/ }
   }
+
+  if (OB_SUCC(ret) && ranges.count() > 1) {
+    // if there is more than one range and it is exists exec params in ranges_exprs, check at most one range.
+    // for (min; max) range extract from range_exprs contain exec params, do nothing now.
+    ObSEArray<ObRawExpr*, 4> cur_const_exprs;
+    ObSEArray<ObRawExpr*, 16> columns;
+    bool has_exec_param = false;
+    if (OB_ISNULL(range_info.get_query_range())) {
+      ret = OB_ERR_UNEXPECTED;
+      LOG_WARN("unexpected NULL", K(ret), K(range_info.get_query_range()));
+      } else if (OB_FAIL(check_has_exec_param(*range_info.get_query_range(), has_exec_param))) {
+      LOG_WARN("failed to check has exec param", K(ret));
+    } else if (OB_FAIL(ObRawExprUtils::extract_column_exprs(range_info.get_query_range()->get_range_exprs(),
+                                                            columns))) {
+      LOG_WARN("failed to extract column exprs", K(ret));
+    } else if (columns.empty() || !has_exec_param) {
+      /* do nothing */
+    } else if (OB_FAIL(ObOptimizerUtil::compute_const_exprs(range_info.get_query_range()->get_range_exprs(),
+                                                            cur_const_exprs))) {
+      // for inner path, const expr is computed without pushdown filter.
+      // need compute const expr by range_exprs.
+      LOG_WARN("failed to compute const exprs", K(ret));
+    } else {
+      bool at_most_one_range = true;
+      for (int64_t i = 0; at_most_one_range && i < columns.count(); ++i) {
+        at_most_one_range = ObOptimizerUtil::find_equal_expr(cur_const_exprs, columns.at(i),
+                                                             get_output_equal_sets());
+      }
+      est_cost_info.at_most_one_range_ = at_most_one_range;
+    }
+  }
   return ret;
 }
 
@@ -997,7 +1029,7 @@ int ObJoinOrder::get_query_range_info(const uint64_t table_id,
   return ret;
 }
 
-int ObJoinOrder::check_has_exec_param(ObQueryRange &query_range,
+int ObJoinOrder::check_has_exec_param(const ObQueryRange &query_range,
                                       bool &has_exec_param)
 {
   int ret = OB_SUCCESS;

src/sql/optimizer/ob_join_order.h

@@ -2183,7 +2183,7 @@ struct NullAwareAntiJoinInfo {
                              QueryRangeInfo &range_info,
                              PathHelper &helper);
 
-    int check_has_exec_param(ObQueryRange &query_range,
+    int check_has_exec_param(const ObQueryRange &query_range,
                              bool &has_exec_param);
 
     int get_preliminary_prefix_info(ObQueryRange &query_range,QueryRangeInfo &range_info);

src/sql/optimizer/ob_opt_est_cost_model.cpp

@@ -102,6 +102,7 @@ int ObCostTableScanInfo::assign(const ObCostTableScanInfo &est_cost_info)
     batch_type_ = est_cost_info.batch_type_;
     sample_info_ = est_cost_info.sample_info_;
     use_column_store_ = est_cost_info.use_column_store_;
+    at_most_one_range_ = est_cost_info.at_most_one_range_;
     // no need to copy table scan param
   }
   return ret;
@@ -1773,7 +1774,11 @@ int ObOptEstCostModel::range_scan_cpu_cost(const ObCostTableScanInfo &est_cost_i
     }
     // CPU代价，包括get_next_row调用的代价和谓词代价
     double range_cost = 0;
-    range_cost = est_cost_info.ranges_.count() * cost_params_.get_range_cost(sys_stat_);
+    double range_count = est_cost_info.ranges_.count();
+    if (range_count > 1 && est_cost_info.at_most_one_range_) {
+      range_count = 1;
+    }
+    range_cost = range_count * cost_params_.get_range_cost(sys_stat_);
     cost = row_count * cost_params_.get_cpu_tuple_cost(sys_stat_);
     cost += range_cost + qual_cost + project_cost;
 

src/sql/optimizer/ob_opt_est_cost_model.h

@@ -229,7 +229,8 @@ struct ObCostTableScanInfo
      index_back_row_count_(0.0),
      output_row_count_(0.0),
      batch_type_(common::ObSimpleBatch::ObBatchType::T_NONE),
-     use_column_store_(false)
+     use_column_store_(false),
+     at_most_one_range_(false)
   { }
   virtual ~ObCostTableScanInfo()
   { }
@@ -290,7 +291,7 @@ struct ObCostTableScanInfo
   SampleInfo sample_info_;
   bool use_column_store_;
   common::ObSEArray<ObCostColumnGroupInfo, 4, common::ModulePageAllocator, true> column_group_infos_;
-
+  bool at_most_one_range_;
 private:
   DISALLOW_COPY_AND_ASSIGN(ObCostTableScanInfo);
 };