* (feature)(cloud) Use dynamic allocator instead of static buffer pool for better elasticity. (#28983)
* [fix](outfile) Fix unable to export empty data (#30703)
Issue Number: close#30600
Fix unable to export empty data to hdfs / S3, this behavior is inconsistent with version 1.2.7,
version 1.2.7 can export empty data to hdfs/ S3, and there will be exported files on S3/HDFS.
* [fix](file-writer) avoid empty file for segment writer (#31169)
---------
Co-authored-by: AlexYue <yj976240184@gmail.com>
Co-authored-by: zxealous <zhouchangyue@baidu.com>
The UTF8 format of the Windows system has BOM.
We add a new user property to `Outfile/Export`。Therefore, when exporting Doris data, users can choose whether to bring BOM on the beginning of the CSV file.
**Usage:**
```sql
-- outfile:
select * from demo.student
into outfile "file:///xxx/export/exp_"
format as csv
properties(
"column_separator" = ",",
"with_bom" = "true"
);
-- Export:
EXPORT TABLE student TO "file:///xx/tmpdata/export/exp_"
PROPERTIES(
"format" = "csv",
"with_bom" = "true"
);
```
If the original data is：
```sql
+-----------------------------------------------------+
| s_info |
+-----------------------------------------------------+
| {"s_id": 2, "s_name": "nereids", "s_address": "20"} |
| {"s_id": 1, "s_name": "doris", "s_address": "18"} |
+-----------------------------------------------------+
```
In the original logic, the struct type data exported to a csv file format did not contain column names,like
```
{2, "nereids", "20"}
{1, "doris", "18"}
```
This pr do not need to be merged into branch-2.0
This pr makes three changes to the display of complex types：
1. NULL value in complex types refers to being displayed as `null`, not `NULL`
2. struct type is displayed as "column_name": column_value
3. Time types such as `datetime` and `date`, are displayed with double quotes in complex types. like
`{1, "2023-10-26 12:12:12"}`
This pr also do a code refactor:
1. nesting_level is set to a member variable of the `DataTypeSerDe`, rather than a parameter in methods.
What's more, this pr fix a bug that fileSize is not correct, introduced by this pr: #25854
This pr do two things:
1. Infer the column name if the column is expression in `select into outfile`. The rule for column name generation can be refered in pr: #24990
2. fix bug that it will core dump if the `_schema` fails to build in the open phase in vorc_transformer.cpp
TODO:
1. Support infer the column name if the column is expression in `select into outfile` in new optimizer(Nereids).
In the original logic, the `Export` statement generates `Selectstmt` for execution. But there is no way to make the `SelectStmt` use the new optimizer.
Now, we change the `Export` statement to generate the `outfile SQL`, and then use the new optimizer to parse the SQL so that outfile can use the new optimizer.
Problem:
It will return a result although we use wrong ak/sk/bucket name, such as:
```sql
mysql> select * from demo.student
-> into outfile "s3://xxxx/exp_"
-> format as csv
-> properties(
-> "s3.endpoint" = "https://cos.ap-beijing.myqcloud.com",
-> "s3.region" = "ap-beijing",
-> "s3.access_key"= "xxx",
-> "s3.secret_key" = "yyyy"
-> );
+------------+-----------+----------+----------------------------------------------------------------------------------------------------+
| FileNumber | TotalRows | FileSize | URL |
+------------+-----------+----------+----------------------------------------------------------------------------------------------------+
| 1 | 3 | 26 | s3://xxxx/exp_2ae166e2981d4c08-b577290f93aa82ba_ |
+------------+-----------+----------+----------------------------------------------------------------------------------------------------+
1 row in set (0.15 sec)
```
The reason for this is that we did not catch the error returned by `close()` phase.
This problem is casued by #21197
Fixed an issue that `csv_with_names` and `csv_with_names_and_types` file format could not be exported on nereids optimizer when using `select...into outfile`.
1. support export `LARGEINT` data type to parquet/orc file format.
2. Export the DORIS `DATE/DATETIME` type to the `Date/Timestamp` logic type of parquet file format.
3. Fix that the data is not correct when the DATE type data is exported to ORC.
