#pragma once #include #include #include #include #include namespace DB { struct TreeRewriterResult; /// Part of of Tree Rewriter (SyntaxAnalyzer) that optimizes AST. /// Query should be ready to execute either before either after it. But resulting query could be faster. class TreeOptimizer { public: static void apply( ASTPtr & query, TreeRewriterResult & result, const std::vector & tables_with_columns, ContextPtr context); static void optimizeIf(ASTPtr & query, Aliases & aliases, bool if_chain_to_multiif); static void optimizeCountConstantAndSumOne(ASTPtr & query); }; }