概要描述

本文介绍如何使用 python 实现 inceptor udf 函数，仅供参考。

详细说明

1. 编写python脚本

功能是实现使用空格做字符串拆分

#!/usr/bin/python
import sys
for line in sys.stdin:
    line = line.strip()
    fname , lname = line.split(' ')
    l_name = lname.lower()
    print '\t'.join([fname, str(l_name)])

2. 将.py文件上传到容器的/usr/lib/inceptor/lib目录，做镜像持久化

3. 构建测试表及测试数据

CREATE TABLE test01(id varchar2(255) ) CLUSTERED by(id) INTO 1 BUCKETS STORED AS ORC_TRANSACTION;

INSERT INTO test01 VALUES('liu kaiwen');
INSERT INTO test01 VALUES('zhang sanfeng');

4. 执行transform语句

SELECT transform(id) USING 'python /usr/lib/inceptor/lib/split.py' AS thing1, thing2 FROM test01;

FAQ：开启kerberos情况下报错问题

开启kerberos情况下会报如下错误：

SQL 错误 [12] [08S01]: FAILED: Hive Internal Error: org.apache.hadoop.hive.ql.security.authorization.plugin.HiveAccessControlException(Query with transform clause is disallowed in current configuration. )

该问题，是因为transform是hive的一个安全漏洞，参考： https://issues.apache.org/jira/browse/RANGER-738

The TRANSFORM statement in Hive is a big security hole with Hive run without impersonation, so when SQL Standard Authorization is enabled, the feature id completely disabled which is a bit of a sledgehammer approach to securing this statement.

argodb 6.0 及以上版本，可以通过参数 set quark.python.transform.enabled=true 解决。