hive 表数据复合 struts类型
STRUCT{a INT; b INT} 通过 c.a 来获得 a的值
create table test1(id INT, info struct<name:STRING, age:INT, sources:Double>)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ',' COLLECTION ITEMS TERMINATED BY ':';
Array类型
array A中元素['a','b','c'],则A[1]的值为'b'
create table test2(name string, stu_id Array<INT>)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ',' COLLECTION ITEMS TERMINATED BY ':';
Map类型 包含了 key ->value 通过 key 获得value的值
create table test3(id string, perf map<string, int>)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ' ' COLLECTION ITEMS TERMINATED BY ',' MAP KEYS TERMINATED BY ':';
hive 不布隆滤器一个行健查询,一个列都可以实现, 布隆占用内存空间很小
布隆过滤器可以实现缓存查询,如果查询不在再到磁盘查询