| /** |
| * 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. |
| **/ |
| |
| #include <vector> |
| #include <unordered_map> |
| |
| #include "query_optimizer/expressions/Alias.hpp" |
| #include "query_optimizer/expressions/AttributeReference.hpp" |
| #include "query_optimizer/expressions/ExprId.hpp" |
| #include "query_optimizer/expressions/Expression.hpp" |
| #include "query_optimizer/expressions/LogicalAnd.hpp" |
| #include "query_optimizer/expressions/NamedExpression.hpp" |
| #include "query_optimizer/expressions/PatternMatcher.hpp" |
| #include "query_optimizer/rules/UpdateExpression.hpp" |
| |
| namespace quickstep { |
| namespace optimizer { |
| |
| namespace E = ::quickstep::optimizer::expressions; |
| |
| std::vector<expressions::PredicatePtr> GetConjunctivePredicates( |
| const expressions::PredicatePtr &predicate) { |
| expressions::LogicalAndPtr logical_and; |
| if (expressions::SomeLogicalAnd::MatchesWithConditionalCast(predicate, &logical_and)) { |
| return logical_and->operands(); |
| } else { |
| return {predicate}; |
| } |
| } |
| |
| void PullUpProjectExpressions( |
| const std::vector<E::NamedExpressionPtr> &project_expressions_for_pullup, |
| const std::vector<std::vector<E::ExpressionPtr>*> &non_project_expression_lists, |
| const std::vector<std::vector<E::NamedExpressionPtr>*> &project_expression_lists) { |
| std::unordered_map<E::ExprId, E::ExpressionPtr> expression_replacement_map; |
| for (const E::NamedExpressionPtr &named_expression : |
| project_expressions_for_pullup) { |
| E::AliasPtr alias; |
| if (E::SomeAlias::MatchesWithConditionalCast(named_expression, &alias)) { |
| const E::ExpressionPtr replacement_expression = alias->expression(); |
| expression_replacement_map.emplace(alias->id(), replacement_expression); |
| } |
| } |
| |
| if (!expression_replacement_map.empty()) { |
| UpdateExpression rule(expression_replacement_map); |
| |
| // For non-project expressions, simply apply the UpdateExpression rule. |
| for (std::vector<E::ExpressionPtr> *non_project_expressions : |
| non_project_expression_lists) { |
| for (std::vector<E::ExpressionPtr>::size_type i = 0; i < non_project_expressions->size(); ++i) { |
| const E::ExpressionPtr &expression_to_update = (*non_project_expressions)[i]; |
| (*non_project_expressions)[i] = rule.apply(expression_to_update); |
| } |
| } |
| |
| for (std::vector<E::NamedExpressionPtr> *project_expressions : |
| project_expression_lists) { |
| for (std::vector<E::NamedExpressionPtr>::size_type i = 0; i < project_expressions->size(); ++i) { |
| const E::NamedExpressionPtr &expression_to_update = (*project_expressions)[i]; |
| E::ExpressionPtr updated_expression = rule.apply(expression_to_update); |
| |
| E::NamedExpressionPtr updated_named_expression; |
| // If the updated expression is not a NamedExpression or we have changed |
| // the ID, restore the ID by adding an Alias. |
| if (!E::SomeNamedExpression::MatchesWithConditionalCast(updated_expression, |
| &updated_named_expression) || |
| expression_to_update->id() != updated_named_expression->id()) { |
| (*project_expressions)[i] = |
| E::Alias::Create(expression_to_update->id(), |
| updated_expression, |
| expression_to_update->attribute_name(), |
| expression_to_update->attribute_alias(), |
| expression_to_update->relation_name()); |
| } else { |
| (*project_expressions)[i] = updated_named_expression; |
| } |
| } |
| } |
| } |
| } |
| |
| } // namespace optimizer |
| } // namespace quickstep |