westonpace commented on a change in pull request #12110:
URL: https://github.com/apache/arrow/pull/12110#discussion_r802350610
##########
File path: cpp/src/arrow/compute/exec/hash_join_node.cc
##########
@@ -275,30 +275,61 @@ Status HashJoinSchema::ValidateSchemas(JoinType
join_type, const Schema& left_sc
}
std::shared_ptr<Schema> HashJoinSchema::MakeOutputSchema(
- const std::string& left_field_name_prefix,
- const std::string& right_field_name_prefix) {
+ const std::string& left_field_name_suffix,
+ const std::string& right_field_name_suffix) {
std::vector<std::shared_ptr<Field>> fields;
int left_size = proj_maps[0].num_cols(HashJoinProjection::OUTPUT);
int right_size = proj_maps[1].num_cols(HashJoinProjection::OUTPUT);
fields.resize(left_size + right_size);
- for (int i = 0; i < left_size + right_size; ++i) {
- bool is_left = (i < left_size);
- int side = (is_left ? 0 : 1);
- int input_field_id = proj_maps[side]
- .map(HashJoinProjection::OUTPUT,
HashJoinProjection::INPUT)
- .get(is_left ? i : i - left_size);
+ std::unordered_multimap<std::string, int> left_field_map;
+ left_field_map.reserve(left_size);
+ for (int i = 0; i < left_size; ++i) {
+ int side = 0; // left
+ int input_field_id =
+ proj_maps[side].map(HashJoinProjection::OUTPUT,
HashJoinProjection::INPUT).get(i);
const std::string& input_field_name =
proj_maps[side].field_name(HashJoinProjection::INPUT, input_field_id);
const std::shared_ptr<DataType>& input_data_type =
proj_maps[side].data_type(HashJoinProjection::INPUT, input_field_id);
+ left_field_map.insert({input_field_name, i});
+ // insert left table field
+ fields[i] =
+ std::make_shared<Field>(input_field_name, input_data_type, true
/*nullable*/);
+ }
- std::string output_field_name =
- (is_left ? left_field_name_prefix : right_field_name_prefix) +
input_field_name;
+ for (int i = 0; i < right_size; ++i) {
+ int side = 1; // right
+ int input_field_id =
+ proj_maps[side].map(HashJoinProjection::OUTPUT,
HashJoinProjection::INPUT).get(i);
+ const std::string& input_field_name =
+ proj_maps[side].field_name(HashJoinProjection::INPUT, input_field_id);
+ const std::shared_ptr<DataType>& input_data_type =
+ proj_maps[side].data_type(HashJoinProjection::INPUT, input_field_id);
+ // search the map and add suffix to the elements which
+ // are present both in left and right tables
+ // auto search = left_field_map.find(input_field_name);
Review comment:
```suggestion
```
--
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: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
