hubgeter commented on code in PR #49051: URL: https://github.com/apache/doris/pull/49051#discussion_r2003308986
########## be/src/vec/exec/format/table/table_format_reader.cpp: ########## @@ -0,0 +1,133 @@ +// 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. + +#include "table_format_reader.h" + +#include <algorithm> +#include <string> + +#include "common/status.h" +#include "vec/core/block.h" +#include "vec/exec/format/generic_reader.h" + +namespace doris::vectorized { +#include "common/compile_check_begin.h" + +Status TableSchemaChangeHelper::init_schema_info( + const std::vector<std::string>& read_table_col_names, + const std::unordered_map<int32_t, std::string>& table_id_to_name, + const std::unordered_map<std::string, ColumnValueRangeType>* + table_col_name_to_value_range) { + bool exist_schema = true; + std::map<int32_t, std::string> file_id_to_name; + RETURN_IF_ERROR(get_file_col_id_to_name(exist_schema, file_id_to_name)); + if (!exist_schema) { + file_id_to_name.clear(); + for (const auto& [table_col_id, table_col_name] : table_id_to_name) { + file_id_to_name.emplace(table_col_id, table_col_name); + } + } + + /** This is to compare the table schema from FE (table_id_to_name) with + * the current file schema (file_id_to_name) , generate two maps for future use: + * 1. table column name to file column name. + * 2. file column name to table column name. + * For example, file has a column 'col1', + * after this file was written, iceberg changed the column name to 'col1_new'. + * The two maps would contain: + * 1. col1_new -> col1 + * 2. col1 -> col1_new + */ + for (const auto& [file_col_id, file_col_name] : file_id_to_name) { + if (table_id_to_name.find(file_col_id) == table_id_to_name.end()) { + continue; + } + + auto& table_col_name = table_id_to_name.at(file_col_id); + _table_col_to_file_col.emplace(table_col_name, file_col_name); + _file_col_to_table_col.emplace(file_col_name, table_col_name); + if (table_col_name != file_col_name) { + _has_schema_change = true; + } + } + + /** Generate _all_required_col_names and _not_in_file_col_names. + * + * _all_required_col_names is all the columns required by user sql. + * If the column name has been modified after the data file was written, + * put the old name in data file to _all_required_col_names. + * + * _not_in_file_col_names is all the columns required by user sql but not in the data file. + * e.g. New columns added after this data file was written. + * The columns added with names used by old dropped columns should consider as a missing column, + * which should be in _not_in_file_col_names. + */ + _all_required_col_names.clear(); + _not_in_file_col_names.clear(); + for (auto table_col_name : read_table_col_names) { + auto iter = _table_col_to_file_col.find(table_col_name); + if (iter == _table_col_to_file_col.end()) { + _all_required_col_names.emplace_back(table_col_name); + _not_in_file_col_names.emplace_back(table_col_name); + } else { + _all_required_col_names.emplace_back(iter->second); + } + } + + /** Generate _new_colname_to_value_range, by replacing the column name in + * _colname_to_value_range with column name in data file. + */ + for (auto& it : *table_col_name_to_value_range) { + auto iter = _table_col_to_file_col.find(it.first); + if (iter == _table_col_to_file_col.end()) { + _new_colname_to_value_range.emplace(it.first, it.second); + } else { + _new_colname_to_value_range.emplace(iter->second, it.second); + } + } + return Status::OK(); +} + +Status TableSchemaChangeHelper::get_next_block_before(Block* block) const { + if (_has_schema_change) { + for (int i = 0; i < block->columns(); i++) { + ColumnWithTypeAndName& col = block->get_by_position(i); + auto iter = _table_col_to_file_col.find(col.name); + if (iter != _table_col_to_file_col.end()) { + col.name = iter->second; + } + } + block->initialize_index_by_name(); + } + return Status::OK(); +} + +Status TableSchemaChangeHelper::get_next_block_after(Block* block) const { Review Comment: I don't think it's necessary. It doesn't bring much performance overhead. It just replaces the name of the column. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org For additional commands, e-mail: commits-h...@doris.apache.org
