From 5a211b1ab74a2f90ada84ae5a58839b271cae36f Mon Sep 17 00:00:00 2001 From: Nikolai Kochetov Date: Thu, 27 Sep 2018 18:16:47 +0300 Subject: [PATCH] More comments. --- dbms/src/Functions/IFunction.cpp | 3 +++ dbms/src/Interpreters/ExpressionActions.h | 3 +++ 2 files changed, 6 insertions(+) diff --git a/dbms/src/Functions/IFunction.cpp b/dbms/src/Functions/IFunction.cpp index e8f35094629..f74eb26cd60 100644 --- a/dbms/src/Functions/IFunction.cpp +++ b/dbms/src/Functions/IFunction.cpp @@ -42,6 +42,9 @@ namespace ErrorCodes } +/// Cache for functions result if it was executed on low cardinality column. +/// It's LRUCache which stores function result executed on dictionary and index mapping. +/// It's expected that cache_size is a number of reading streams (so, will store single cached value per thread). class PreparedFunctionLowCardinalityResultCache { public: diff --git a/dbms/src/Interpreters/ExpressionActions.h b/dbms/src/Interpreters/ExpressionActions.h index eec0ab7e903..4dc81c7d938 100644 --- a/dbms/src/Interpreters/ExpressionActions.h +++ b/dbms/src/Interpreters/ExpressionActions.h @@ -89,8 +89,11 @@ public: ColumnPtr added_column; /// For APPLY_FUNCTION and LEFT ARRAY JOIN. + /// FunctionBuilder is used before action was added to ExpressionActions (when we don't know types of arguments). FunctionBuilderPtr function_builder; + /// Can be used after action was added to ExpressionActions if we want to get function signature or properties like monotonicity. FunctionBasePtr function_base; + /// Prepared function which is used in function execution. PreparedFunctionPtr function; Names argument_names; bool is_function_compiled = false;