| /** |
| * Copyright 2011-2015 Quickstep Technologies LLC. |
| * Copyright 2015 Pivotal Software, Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| **/ |
| |
| #ifndef QUICKSTEP_QUERY_OPTIMIZER_PHYSICAL_GENERATOR_HPP_ |
| #define QUICKSTEP_QUERY_OPTIMIZER_PHYSICAL_GENERATOR_HPP_ |
| |
| #include <memory> |
| #include <unordered_map> |
| #include <vector> |
| |
| #include "query_optimizer/LogicalToPhysicalMapper.hpp" |
| #include "query_optimizer/logical/Logical.hpp" |
| #include "query_optimizer/physical/Physical.hpp" |
| #include "query_optimizer/strategy/Strategy.hpp" |
| #include "utility/Macros.hpp" |
| |
| namespace quickstep { |
| namespace optimizer { |
| |
| /** \addtogroup QueryOptimizer |
| * @{ |
| */ |
| |
| /** |
| * @brief Converts logical plans to physical plans. |
| */ |
| class PhysicalGenerator : public LogicalToPhysicalMapper { |
| public: |
| /** |
| * @brief Constructor |
| */ |
| PhysicalGenerator() { |
| createStrategies(); |
| } |
| |
| /** |
| * @brief Destructor. |
| */ |
| ~PhysicalGenerator() {} |
| |
| /** |
| * @return The generated physical plan. |
| */ |
| const physical::PhysicalPtr& physical_plan() const { return physical_plan_; } |
| |
| /** |
| * @brief Generates and optimizes a physical plan for \p logical_plan. |
| * |
| * @param logical_plan The logical plan to be converted to a physical plan. |
| * @return The physical plan. |
| */ |
| physical::PhysicalPtr generatePlan(const logical::LogicalPtr &logical_plan); |
| |
| /** |
| * @brief Sets the best physical plan for \p logical_plan is \p physical_plan. |
| * |
| * @param logical_plan Logical plan. |
| * @param physical_plan The physical plan for the logical plan. |
| */ |
| void setBestPhysicalForLogical(const logical::LogicalPtr &logical_plan, |
| const physical::PhysicalPtr &physical_plan); |
| |
| physical::PhysicalPtr createOrGetPhysicalFromLogical( |
| const logical::LogicalPtr &logical_plan) final; |
| |
| private: |
| /** |
| * @brief Creates an initial physical plan for \p logical_plan. |
| * It tries each strategy to the logical plan in order, |
| * and the physical plan generated by the first strategy that can |
| * be applied is chosen as the best initial physical plan. |
| * |
| * |
| * @param logical_plan The logical plan to be converted to a physical plan. |
| * @return The initial physical plan. |
| */ |
| physical::PhysicalPtr generateInitialPlan( |
| const logical::LogicalPtr &logical_plan); |
| |
| /** |
| * @brief Creates strategies for different types of physical nodes. |
| */ |
| void createStrategies(); |
| |
| /** |
| * @brief Applies physical rules to the initial physical plan. |
| * |
| * @return The optimized physical plan. |
| */ |
| physical::PhysicalPtr optimizePlan(); |
| |
| std::vector<std::unique_ptr<strategy::Strategy>> strategies_; |
| |
| /** |
| * @brief Maps a logical plan to its initial physical plan. |
| * We memorize every generated sub-physical plan in this map. |
| * This map is currently useless, because each logical node is |
| * visited only once and its physical plan won't be retrieved |
| * from the map. This is used to allow strategy tests to change |
| * the plans created for a logical plan by putting intended plans |
| * into the map so that the generator won't apply a strategy to |
| * create a plan for a logical node. It also makes testing on |
| * different strategies to be relatively independent. A strategy test |
| * only checks one type of physical plans, and manually provides other |
| * types of physical plans that are not interested. This map will become |
| * more useful when we have a cost model to evaluate the cost of a |
| * physical plan. The best physical plan for a logical subplan may be shared |
| * in multiple physical plans during the plan enumeration. |
| */ |
| std::unordered_map<logical::LogicalPtr, physical::PhysicalPtr> logical_to_physical_map_; |
| |
| /** |
| * @brief The complete physical plan. |
| */ |
| physical::PhysicalPtr physical_plan_; |
| |
| DISALLOW_COPY_AND_ASSIGN(PhysicalGenerator); |
| }; |
| |
| /** @} */ |
| |
| } // namespace optimizer |
| } // namespace quickstep |
| |
| #endif /* QUICKSTEP_QUERY_OPTIMIZER_PHYSICAL_GENERATOR_HPP_ */ |