Hive lateral view 和 explode 详解

create table if not exists employees ( 
name         string, 
salary       float, 
subordinates array<string>, 
deductions   map<string, float>, 
address      struct<street:string, city:string, state:string, zip:int> 
) 
row format delimited 
fields terminated by '\001'  
collection items terminated by '\002'  
map keys terminated by '\003' 
lines terminated by '\n' 
stored as textfile;

select name,subordinate from employees lateral view explode(subordinates) subordinates_table as subordinate; 

create table if not exists doc(text string) row format delimited lines terminated by '\n';

load data local inpath '/opt/hadoop-2.7.4/README.txt' overwrite into table doc;

select word, count(*) from doc lateral view explode(split(text,' ')) ITable as word group by word;