diff --git a/dbms/src/Processors/Transforms/FilterTransform.cpp b/dbms/src/Processors/Transforms/FilterTransform.cpp index dc9b973e003..593c86e6c27 100644 --- a/dbms/src/Processors/Transforms/FilterTransform.cpp +++ b/dbms/src/Processors/Transforms/FilterTransform.cpp @@ -5,17 +5,12 @@ namespace DB { -static Block transformHeader( - Block header, - const ExpressionActionsPtr & expression, - const String & filter_column_name, - bool remove_filter_column) +static void replaceFilterToConstant(Block & block, const String & filter_column_name) { - expression->execute(header); ConstantFilterDescription constant_filter_description; - auto filter_column = header.getPositionByName(filter_column_name); - auto & column_elem = header.safeGetByPosition(filter_column); + auto filter_column = block.getPositionByName(filter_column_name); + auto & column_elem = block.safeGetByPosition(filter_column); /// Isn't the filter already constant? if (column_elem.column) @@ -26,11 +21,22 @@ static Block transformHeader( { /// Replace the filter column to a constant with value 1. FilterDescription filter_description_check(*column_elem.column); - column_elem.column = column_elem.type->createColumnConst(header.rows(), 1u); + column_elem.column = column_elem.type->createColumnConst(block.rows(), 1u); } +} + +static Block transformHeader( + Block header, + const ExpressionActionsPtr & expression, + const String & filter_column_name, + bool remove_filter_column) +{ + expression->execute(header); if (remove_filter_column) header.erase(filter_column_name); + else + replaceFilterToConstant(header, filter_column_name); return header; } @@ -45,8 +51,13 @@ FilterTransform::FilterTransform( , filter_column_name(std::move(filter_column_name_)) , remove_filter_column(remove_filter_column) { - transformed_header = transformHeader(getInputPort().getHeader(), expression, filter_column_name, false); + transformed_header = getInputPort().getHeader(); + expression->execute(transformed_header); filter_column_position = transformed_header.getPositionByName(filter_column_name); + + auto & column = transformed_header.getByPosition(filter_column_position).column; + if (column) + constant_filter_description = ConstantFilterDescription(*column); } IProcessor::Status FilterTransform::prepare()