| /** |
| * 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_AGGREGATE_FUNCTION_HPP_ |
| #define QUICKSTEP_QUERY_OPTIMIZER_EXPRESSIONS_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 AggregateFunction; |
| class Type; |
| |
| namespace optimizer { |
| namespace expressions { |
| |
| /** \addtogroup OptimizerExpressions |
| * @{ |
| */ |
| |
| class AggregateFunction; |
| typedef std::shared_ptr<const AggregateFunction> AggregateFunctionPtr; |
| |
| /** |
| * @brief Represents an aggregate 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 AggregateFunction : public Expression { |
| public: |
| /** |
| * @brief Destructor. |
| */ |
| ~AggregateFunction() override {} |
| |
| ExpressionType getExpressionType() const override { |
| return ExpressionType::kAggregateFunction; |
| } |
| |
| std::string getName() const override { |
| return "AggregateFunction"; |
| } |
| |
| const Type& getValueType() const override; |
| |
| bool isConstant() const override { |
| // 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 True if this aggregate is a vector aggregate (i.e. with GROUP BY). |
| **/ |
| inline bool is_vector_aggregate() const { |
| return is_vector_aggregate_; |
| } |
| |
| /** |
| * @return The AggregateFunction singleton (from the expression system) |
| * for this node. |
| **/ |
| inline const ::quickstep::AggregateFunction& getAggregate() const { |
| return aggregate_; |
| } |
| |
| /** |
| * @return The list of scalar arguments to this aggregate. |
| **/ |
| inline const std::vector<ScalarPtr>& getArguments() const { |
| return arguments_; |
| } |
| |
| /* |
| * @return Whether this is a DISTINCT aggregation. |
| */ |
| inline bool is_distinct() const { |
| return is_distinct_; |
| } |
| |
| /** |
| * @brief Create a new AggregateFunction. |
| * |
| * @warning It is an error to call this with arguments that the given |
| * aggregate can not apply to. |
| * |
| * @param aggregate The underlying AggregateFunction from the expression |
| * system. |
| * @param arguments A list of arguments to the aggregate function. |
| * @param is_vector_aggregate Whether the aggregate has a GROUP BY clause. |
| * @param is_distinct Whether this is a DISTINCT aggregation. |
| * @return A new AggregateFunctionPtr. |
| **/ |
| static AggregateFunctionPtr Create(const ::quickstep::AggregateFunction &aggregate, |
| const std::vector<ScalarPtr> &arguments, |
| const bool is_vector_aggregate, |
| 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 aggregate The actual AggregateFunction to use. |
| * @param arguments The scalar arguments to the aggregate function. |
| * @param is_vector_aggregate Indicates whether this aggregation is a vector |
| * aggregation (i.e. GROUP BY exists). |
| * @param is_distinct Indicates whether this is a DISTINCT aggregation. |
| */ |
| AggregateFunction(const ::quickstep::AggregateFunction &aggregate, |
| const std::vector<ScalarPtr> &arguments, |
| const bool is_vector_aggregate, |
| const bool is_distinct) |
| : aggregate_(aggregate), |
| arguments_(arguments), |
| is_vector_aggregate_(is_vector_aggregate), |
| is_distinct_(is_distinct) { |
| for (const ScalarPtr &child : arguments_) { |
| addChild(child); |
| } |
| } |
| |
| const ::quickstep::AggregateFunction &aggregate_; |
| const std::vector<ScalarPtr> arguments_; |
| const bool is_vector_aggregate_; |
| const bool is_distinct_; |
| |
| DISALLOW_COPY_AND_ASSIGN(AggregateFunction); |
| }; |
| |
| /** @} */ |
| |
| } // namespace expressions |
| } // namespace optimizer |
| } // namespace quickstep |
| |
| #endif /* QUICKSTEP_QUERY_OPTIMIZER_EXPRESSIONS_AGGREGATE_FUNCTION_HPP_ */ |