概述
- Virtual Columns
- Simple Examples
Virtual Columns
Hive 0.8.0 provides support for two virtual columns:
One is INPUT__FILE__NAME
, which is the input file's name for a mapper task.
the other is BLOCK__OFFSET__INSIDE__FILE
, which is the current global file position.
For block compressed file, it is the current block's file offset, which is the current block's first byte's file offset.
Simple Examples
select INPUT__FILE__NAME
, key, BLOCK__OFFSET__INSIDE__FILE
from src;
select key, count(INPUT__FILE__NAME
) from src group by key order by key;
select * from src where BLOCK__OFFSET__INSIDE__FILE
> 12000 order by key;
转载于:https://www.cnblogs.com/tmeily/p/4249954.html
最后
以上就是成就便当为你收集整理的[Hive - LanguageManual] VirtualColumns的全部内容,希望文章能够帮你解决[Hive - LanguageManual] VirtualColumns所遇到的程序开发问题。
如果觉得靠谱客网站的内容还不错,欢迎将靠谱客网站推荐给程序员好友。
本图文内容来源于网友提供,作为学习参考使用,或来自网络收集整理,版权属于原作者所有。
发表评论 取消回复