| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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_EXPRESSIONS_WINDOW_AGGREGATE_FUNCTION_HPP_ |
| #define QUICKSTEP_QUERY_OPTIMIZER_EXPRESSIONS_WINDOW_AGGREGATE_FUNCTION_HPP_ |
| |
| #include <memory> |
| #include <string> |
| #include <vector> |
| |
| #include "query_optimizer/OptimizerTree.hpp" |
| #include "query_optimizer/expressions/AttributeReference.hpp" |
| #include "query_optimizer/expressions/Expression.hpp" |
| #include "query_optimizer/expressions/ExpressionType.hpp" |
| #include "query_optimizer/expressions/Scalar.hpp" |
| #include "utility/Macros.hpp" |
| |
| namespace quickstep { |
| |
| class Type; |
| class WindowAggregateFunction; |
| |
| namespace optimizer { |
| namespace expressions { |
| |
| /** \addtogroup OptimizerExpressions |
| * @{ |
| */ |
| |
| struct WindowFrameInfo { |
| /** |
| * @brief Cosntructor. |
| * |
| * @param is_row_in True if this window frame is defined by ROWS, false if |
| * defined by RANGE. |
| * @param num_preceding_in The number of preceding tuples the window frame |
| * will cover, -1 means UNBOUNDED. |
| * @param num_following_in The number of following tuples the window frame |
| * will cover, -1 means UNBOUNDED. |
| **/ |
| WindowFrameInfo(const bool is_row_in, |
| const int num_preceding_in, |
| const int num_following_in) |
| : is_row(is_row_in), |
| num_preceding(num_preceding_in), |
| num_following(num_following_in) {} |
| |
| const bool is_row; |
| const int num_preceding; |
| const int num_following; |
| }; |
| |
| struct WindowInfo { |
| /** |
| * @brief Constructor. |
| * |
| * @param partition_by_attributes_in The partition keys for the window. |
| * @param order_by_attributes_in The order keys for the window. |
| * @param order_by_directions_in The order direction for order key. |
| * @param nulls_first_in The nulls' position for order key. |
| * @param frame_info_in The window frame information for the window. Null |
| * means there is no explicit window frame definition. |
| **/ |
| WindowInfo(const std::vector<AttributeReferencePtr> &partition_by_attributes_in, |
| const std::vector<AttributeReferencePtr> &order_by_attributes_in, |
| const std::vector<bool> &order_by_directions_in, |
| const std::vector<bool> &nulls_first_in, |
| const WindowFrameInfo *frame_info_in) |
| : partition_by_attributes(partition_by_attributes_in), |
| order_by_attributes(order_by_attributes_in), |
| order_by_directions(order_by_directions_in), |
| nulls_first(nulls_first_in), |
| frame_info(frame_info_in) {} |
| |
| const std::vector<AttributeReferencePtr> partition_by_attributes; |
| const std::vector<AttributeReferencePtr> order_by_attributes; |
| const std::vector<bool> order_by_directions; |
| const std::vector<bool> nulls_first; |
| const WindowFrameInfo *frame_info; |
| }; |
| |
| class WindowAggregateFunction; |
| typedef std::shared_ptr<const WindowAggregateFunction> WindowAggregateFunctionPtr; |
| |
| /** |
| * @brief Represents a window aggregate function and its arguments in the |
| * optimizer. This class wraps some of the functionality from |
| * quickstep::AggregateFunction and represents a particular instance |
| * of an aggregate during query optimization. |
| **/ |
| class WindowAggregateFunction : public Expression { |
| public: |
| /** |
| * @brief Destructor. |
| */ |
| ~WindowAggregateFunction() override {} |
| |
| ExpressionType getExpressionType() const override { |
| return ExpressionType::kWindowAggregateFunction; |
| } |
| |
| std::string getName() const override { |
| return "WindowAggregateFunction"; |
| } |
| |
| const Type& getValueType() const override; |
| |
| bool isConstant() const override { |
| // Window aggregate function is never considered as a constant expression. |
| return false; |
| } |
| |
| ExpressionPtr copyWithNewChildren( |
| const std::vector<ExpressionPtr> &new_children) const override; |
| |
| std::vector<AttributeReferencePtr> getReferencedAttributes() const override; |
| |
| /** |
| * @return Whether the type of the return value is nullable. |
| **/ |
| bool isNullable() const; |
| |
| /** |
| * @return The WindowAggregateFunction singleton (from the expression system) |
| * for this node. |
| **/ |
| inline const ::quickstep::WindowAggregateFunction& window_aggregate() const { |
| return window_aggregate_; |
| } |
| |
| /** |
| * @return The list of scalar arguments to this aggregate. |
| **/ |
| inline const std::vector<ScalarPtr>& arguments() const { |
| return arguments_; |
| } |
| |
| /** |
| * @return The window info of this window aggregate function. |
| **/ |
| inline const WindowInfo window_info() const { |
| return window_info_; |
| } |
| |
| /** |
| * @return The name of the window. |
| **/ |
| inline const std::string window_name() const { |
| return window_name_; |
| } |
| |
| /** |
| * @return Whether this is a DISTINCT aggregation. |
| **/ |
| inline bool is_distinct() const { |
| return is_distinct_; |
| } |
| |
| /** |
| * @brief Create a new WindowAggregateFunction by directly defined window. |
| * |
| * @warning It is an error to call this with arguments that the given |
| * aggregate can not apply to. |
| * |
| * @param aggregate The underlying WindowAggregateFunction from the expression |
| * system. |
| * @param arguments A list of arguments to the window aggregate function. |
| * @param window_info The window info of the window aggregate function. |
| * @param is_distinct Whether this is a DISTINCT aggregation. |
| * @return A new AggregateFunctionPtr. |
| **/ |
| static WindowAggregateFunctionPtr Create(const ::quickstep::WindowAggregateFunction &window_aggregate, |
| const std::vector<ScalarPtr> &arguments, |
| const WindowInfo &window_info, |
| const std::string &window_name, |
| const bool is_distinct); |
| |
| protected: |
| void getFieldStringItems( |
| std::vector<std::string> *inline_field_names, |
| std::vector<std::string> *inline_field_values, |
| std::vector<std::string> *non_container_child_field_names, |
| std::vector<OptimizerTreeBaseNodePtr> *non_container_child_fields, |
| std::vector<std::string> *container_child_field_names, |
| std::vector<std::vector<OptimizerTreeBaseNodePtr>> *container_child_fields) const override; |
| |
| private: |
| /** |
| * @brief Constructor. |
| * |
| * @param window_aggregate The actual AggregateFunction to use. |
| * @param arguments A list of arguments to the window aggregate function. |
| * @param window_info The window info of the window aggregate function. |
| * @param is_distinct Indicates whether this is a DISTINCT aggregation. |
| */ |
| WindowAggregateFunction(const ::quickstep::WindowAggregateFunction &window_aggregate, |
| const std::vector<ScalarPtr> &arguments, |
| const WindowInfo &window_info, |
| const std::string &window_name, |
| const bool is_distinct) |
| : window_aggregate_(window_aggregate), |
| arguments_(arguments), |
| window_info_(window_info), |
| window_name_(window_name), |
| is_distinct_(is_distinct) { |
| for (const ScalarPtr &child : arguments_) { |
| addChild(child); |
| } |
| } |
| |
| // TODO(Shixuan): Currently this class uses AggregationFunction as |
| // window_aggregate_. If it really needs to be seperated from the |
| // AggregationFunction, a new class for WindowAggregationFunction should be |
| // created as quickstep::WindowAggregateFunction. |
| const ::quickstep::WindowAggregateFunction &window_aggregate_; |
| const std::vector<ScalarPtr> arguments_; |
| const WindowInfo window_info_; |
| const std::string window_name_; |
| const bool is_distinct_; |
| |
| DISALLOW_COPY_AND_ASSIGN(WindowAggregateFunction); |
| }; |
| |
| /** @} */ |
| |
| } // namespace expressions |
| } // namespace optimizer |
| } // namespace quickstep |
| |
| #endif // QUICKSTEP_QUERY_OPTIMIZER_EXPRESSIONS_WINDOW_AGGREGATE_FUNCTION_HPP_ |