Pig和Hive对比
| Apache Pig uses a language called Pig Latin. It was originally created atYahoo. | Hive uses a language called HiveQL. It was originally created at Facebook. |
| Pig Latin is a data flow language. | HiveQL is a query processing language. |
| Pig Latin is a procedural language and it fits in pipeline paradigm. | HiveQL is a declarative language. |
| Apache Pig can handle structured, unstructured, and semi-structured data. | Hive is mostly for structured data. |
Pig执行模式
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1. local
所有文件都在本地，for test
2. mapreduce
数据在HDFS上
Pig运行模式
1. 交互模式（grunt shell）
输入-执行-输出
2. batch mode 批处理模式
编写pig为扩展名的pig脚本
3. enbed mode 嵌入式
编写udf，在脚本使用
安装PIG
1. download pig
wget https://mirrors.tuna.tsinghua.edu.cn/apache/pig/latest/pig-0.16.0.tar.gz
tar -zxvf pig-0.16.0.tar.gz
ln -s pig-0.16.0.tar.gz pig
2. config ~/.bashrc
vi ~/.bashrc
export PIG_HOME=/usr/local/pig
export PATH=:$PIG_HOME/bin
source ~/.bashrc
3. verify
pig -version
参考：
http://pig.apache.org/docs/r0.16.0/
https://www.tutorialspoint.com/apache_pig/index.htm