4d516bece8
Describe the overview of changes. 1. add function element_at; 2. support element_subscript([]) to get element of array, col_array[N] <==> element_at(col_array, N); 3. return error message instead of BE crash while array function execute failed; element_at(array, index) desc: > Returns element of array at given **(1-based)** index. If **index < 0**, accesses elements from the last to the first. Returns NULL if the index exceeds the length of the array or the array is NULL. Usage example: 1. create table with ARRAY type column and insert some data: ``` +------+------+--------+ | k1 | k2 | k3 | +------+------+--------+ | 1 | 2 | [1, 2] | | 2 | 3 | NULL | | 4 | NULL | [] | | 3 | NULL | NULL | +------+------+--------+ ``` 2. enable vectorized: ``` set enable_vectorized_engine=true; ``` 3. element_subscript([]) usage example: ``` > select k1,k3,k3[1] from array_test; +------+--------+----------------------------+ | k1 | k3 | %element_extract%(`k3`, 1) | +------+--------+----------------------------+ | 3 | NULL | NULL | | 1 | [1, 2] | 1 | | 2 | NULL | NULL | | 4 | [] | NULL | +------+--------+----------------------------+ ``` 4. element_at function usage example: ``` > select k1,k3 from array_test where element_at(k3, -1) = 2; +------+--------+ | k1 | k3 | +------+--------+ | 1 | [1, 2] | +------+--------+ ```
Apache Doris (incubating)
Doris is an MPP-based interactive SQL data warehousing for reporting and analysis. Its original name was Palo, developed in Baidu. After donated to Apache Software Foundation, it was renamed Doris.
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Doris provides high concurrent low latency point query performance, as well as high throughput queries of ad-hoc analysis.
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Doris provides batch data loading and real-time mini-batch data loading.
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Doris provides high availability, reliability, fault tolerance, and scalability.
The main advantages of Doris are the simplicity (of developing, deploying and using) and meeting many data serving requirements in a single system. For details, refer to Overview.
Official website: https://doris.apache.org/
License
Note
Some licenses of the third-party dependencies are not compatible with Apache 2.0 License. So you need to disable some Doris features to be complied with Apache 2.0 License. For details, refer to the
thirdparty/LICENSE.txt
Technology
Doris mainly integrates the technology of Google Mesa and Apache Impala, and it is based on a column-oriented storage engine and can communicate by MySQL client.
Compile and install
See Compilation
Getting start
See Basic Usage
Report issues or submit pull request
If you find any bugs, feel free to file a GitHub issue or fix it by submitting a pull request.
Contact Us
Contact us through the following mailing list.
| Name | Scope | |||
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| dev@doris.apache.org | Development-related discussions | Subscribe | Unsubscribe | Archives |
Links
- Doris official site - http://doris.incubator.apache.org
- Developer Mailing list - dev@doris.apache.org. Mail to dev-subscribe@doris.apache.org, follow the reply to subscribe the mail list.
- Slack channel - Join the Slack