Hive

alter table poi_release.map_poi_hn_click_validity_problem  add partition(dt = '2021-10-01');

select * from poi_release.map_poi_hn_click_validity_problem where dt = '2021-10-01'

hive> load data inpath 'hdfs:///user/hive/warehouse/poi_release.db/map_poi_hn_click_validity_problem/dt=2021-11-12/part-00100-dae5801c-df2d-400f-9eec-bdb4bc5d1bd6-c000' 
overwrite into table poi_release.map_poi_hn_click_validity_problem partition(dt = '2021-10-01');

hdfs dfs -cp /user/hive/warehouse/poi_release.db/map_poi_hn_click_validity_problem/dt=2021-11-12/part-00100-a94b51a4-c7b8-4ffe-9c8e-bcf96d09850c-c000 
/user/hive/warehouse/poi_release.db/map_poi_hn_click_validity_problem/dt=2021-10-01

hdfs dfs -ls /user/hive/warehouse/poi_release.db/map_poi_hn_click_validity_problem/dt=2021-10-01

show partitions poi_release.map_poi_hn_click_validity_problem;
alter table poi_release.map_poi_hn_click_validity_problem drop partition (dt = '2021-10-01');

基于Hadoop开源数据框架工具Hive，本质上是将HDFS上的数据映射成数据库、数据表等元数据，然后再对这些文件进行检索查询。

1、内部表：导入数据时，将数据移动到hive指定的目录文件中，删除表时，数据也会删除；

2、外部表：建表时添加关键字external，并指定位置，删除表时不会删除源数据。

一、数据

1,tom,music-running-code,c++:98.0-java:76.0-php:65.0
2,jerry,music-code,c++:93.0-java:70.0-php:55.0
3,john,code,go:87.0-python:93.0
二、建表语句

CREATE TABLE table1 (
  id int,
  name string,
  interest array<string>,
  score map<string,string>
 )
row format delimited fields terminated by ','  --列分割
collection items terminated by '-'                  --array分割
map keys terminated by ':'                           --map分割
stored AS textfile;                                       --保存
三、导入数据

load data local inpath '/opt/data/test' overwrite into table table1;

外部表

create external table table2(
id int,name string,interest array<string>,
score map<string,string>)
row format delimited fields terminated by ','
collection items terminated by '-'
map keys terminated by ':' location '/testtable';

desc formatted table2;
创建分区表

create external table table2(
id int,name string,interest array<string>,
score map<string,string>)
partitioned by (year int)
row format delimited fields terminated by ','
collection items terminated by '-'
map keys terminated by ':' stored as textfile;

load data local inpath 'root/testdata.txt' into table
table3 partition(year=2018);

show partitions tables;

alter table table3 add partition(year=2019) 
location '/testtable';

show partitions table3;

alter table table3 drop partition(year=2019);