Hive/Pig 语法简单比较

一句话，Hive 开发比 Pig快多了...

从hdfs读取数据：

Hive: CREATE EXTRENAL TABLE IF NOT EXIST (domain string, num int) ROW FORMAT DELIMITED FIELDS TERMINATED BY ‘\t‘ location ‘hdfs_file‘;

Pig: LOAD ‘hdfs_file‘ USING PigStorage (‘\t‘) as (domain:chararray, num:int);

存储：

Hive: INSERT OVERWRITE DIRECTORY ‘target_hdfs_file‘ SELECT... ;

Pig: STORE result into ‘target_hdfs_file‘;

同SQL的比较：

Hive没有in和not in，"select a.key where a.key in {select b.key from b}"的实现方式为"select a.key from a left outer join b on a.key=b.key where b.key is not null;"

Pig就更麻烦了...

区别：

Pig存储默认分隔符‘\t‘, Hive为‘Ctrl+A‘