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【DM版本】: dm8
【操作系统】：linux
【CPU】: x84
【问题描述】*：
在执行merge into 语句, 希望能得到具体执行的update动作还是insert动作；目前查看文档所知，merge语句并不支持返回值

CREATE TABLE IF NOT EXISTS person (
    id bigint PRIMARY KEY AUTO_INCREMENT,
    name character varying(50 char) default '',
    age bigint default 0,
	sex char(10) default 'm',
    active tinyint default 0,
	is_delete tinyint default 0,
	constraint idx_test_name unique(name, sex)
);

MERGE INTO "person" 
USING (SELECT 'test_1',21,'female',true,false FROM DUAL 
UNION ALL SELECT 'test_2',22,'female',true,false FROM DUAL 
UNION ALL SELECT 'test_4',23,'female',true,false FROM DUAL
UNION ALL SELECT 'test_3',23,'female',true,false FROM DUAL
) AS "excluded" ("name","age","sex","active","is_delete" ) ON "person"."name" = "excluded"."name" AND "person"."sex" = "excluded"."sex" 
WHEN MATCHED THEN UPDATE SET "age"="excluded"."age","active"="excluded"."active"
WHEN NOT MATCHED THEN INSERT ("name","age","sex","active","is_delete") VALUES ("excluded"."name","excluded"."age","excluded"."sex","excluded"."active","excluded"."is_delete")

Oracle数据库中merge into 语句可支持 output子句，试了dm8发现不支持参考，如下

MERGE INTO "person" 
USING (SELECT 'test_1',21,'female',true,false FROM DUAL 
UNION ALL SELECT 'test_2',22,'female',true,false FROM DUAL 
UNION ALL SELECT 'test_4',23,'female',true,false FROM DUAL
UNION ALL SELECT 'test_3',23,'female',true,false FROM DUAL
) AS "excluded" ("name","age","sex","active","is_delete" ) ON "person"."name" = "excluded"."name" AND "person"."sex" = "excluded"."sex" 
WHEN MATCHED THEN UPDATE SET "age"="excluded"."age","active"="excluded"."active"
WHEN NOT MATCHED THEN INSERT ("name","age","sex","active","is_delete") VALUES ("excluded"."name","excluded"."age","excluded"."sex","excluded"."active","excluded"."is_delete")
OUTPUT $ACTION AS action

或者说数据库行记录中是否有对应的伪列（例如postgres的隐藏列xmax），可基于它实现所需的诉求？