当前位置:网站首页>GBase 8c 函数/存储过程参数(二)
GBase 8c 函数/存储过程参数(二)
2022-07-03 02:18:00 【大壮十二】
- RETURNS NULL ON NULL INPUT | STRICT:RETURNS NULL ON NULL INPUT或STRICT用于指定如果函数的某个参数是NULL,此函数总是返回NULL。如果声明了该参数,当有NULL值参数时该函数不会被执行;而只是自动返回一个NULL结果;
- [EXTERNAL] SECURITY INVOKER:表明该函数将带着调用它的用户的权限执行,该参数可以省略,EXTERNAL为可选参数;
- [EXTERNAL] SECURITY DEFINER:声明该函数将以创建它的用户的权限执行EXTERNAL为可选参数;
- PARALLEL:表示该函数是否可以下推到DN上执行。PARALLEL UNSAFE表示该函数不能下推到DN上执行且强制使用顺序执行计划,为默认选项;PARALLEL RESTRICTED表示该函数能下推到DN上执行,但是要求必须在DN Leader上执行;PARALLEL SAFE表示该函数能下推到DN上执行,安全且不受限制;
- execution_cost:用来估计函数的执行成本,execution_cost以cpu_operator_cost为单位,取值范围为正数;
- result_rows:估计函数返回的行数,用于函数返回的是一个集合,取值范围为正数,默认值1000行;
- configuration_parameter:把指定的数据库会话参数值设置为给定的值,如果value是DEFAULT或者RESET,则在新的会话中使用系统的缺省设置。OFF关闭设置,取值范围为字符串;
- definition:定义该函数的字符串常量,可以是内部函数名、对象文件的路径、SQL命令或者用过程语言编写的文本;
- obj_file, link_symbol:适用于C语言函数,字符串obj_file指定了动态库的绝对路径;link_symbol 指定了该函数的链接符号,也就是该函数在C代码中的函数名称;
- attribute:函数可选信息,取值范围:isStrict(等效于STRICT或者RETURNS NULL ON NULL INPUT)、isCachable(等效于IMMUTABLE)。
边栏推荐
- leetcode961. Find the elements repeated N times in the array with length 2n
- The use of Flink CDC mongodb and the implementation of Flink SQL parsing complex nested JSON data in monggo
- Awk from getting started to getting into the ground (3) the built-in functions printf and print of awk realize formatted printing
- stm32F407-------ADC
- Machine learning process and method
- 线程安全的单例模式
- 返回一个树形结构数据
- Swift开发学习
- udp接收队列以及多次初始化的测试
- Thread safe singleton mode
猜你喜欢
What are MySQL locks and classifications
y54.第三章 Kubernetes从入门到精通 -- ingress(二七)
Redis: simple use of redis
awk从入门到入土(0)awk概述
Thread safe singleton mode
Flink CDC mongoDB 使用及Flink sql解析monggo中复杂嵌套JSON数据实现
[shutter] shutter debugging (debugging fallback function | debug method of viewing variables in debugging | console information)
Visual yolov5 format data set (labelme JSON file)
Machine learning notes (constantly updating...)
Y54. Chapter III kubernetes from introduction to mastery -- ingress (27)
随机推荐
Cancellation of collaboration in kotlin, side effects of cancellation and overtime tasks
Anna: Beibei, can you draw?
SPI机制
COM and cn
微信小程序開發工具 POST net::ERR_PROXY_CONNECTION_FAILED 代理問題
去除网页滚动条方法以及内外边距
Return a tree structure data
Basic operation of view
y54.第三章 Kubernetes从入门到精通 -- ingress(二七)
[Yu Yue education] Jiujiang University material analysis and testing technology reference
2022 spring "golden three silver four" job hopping prerequisites: Software Test interview questions (with answers)
awk从入门到入土(0)awk概述
【CodeForces】CF1338A - Powered Addition【二进制】
Codeforces Round #418 (Div. 2) D. An overnight dance in discotheque
Su Shimin: 25 principles of work and life
Producer consumer model based on thread pool (including blocking queue)
8 free, HD, copyright free video material download websites are recommended
返回一个树形结构数据
stm32F407-------DMA
Unrecognized SSL message, plaintext connection?