Shulou(Shulou.com)06/03 Report--

Create table create table mydb.userinfo (name string,addressi string) ROW FORMAT DELIMITEDFIELDS TERMINATED BY'\ t'LINES TERMINATED BY'\ n'STORED AS TEXTFILE; create partition table CREATE TABLE mydb.userinfo-create tables (col1 string, col2 date, col3 double), partitioned by (datekey date),-- combined partition ROW FORMAT DELIMITEDFIELDS TERMINATED BY', 'Stored AS TEXTFILE; data can be imported into table mydb.userinfo load data local inpath "/ home/dahaizi/data/userinfo.txt" overwrite into table mydb.userinfo Insert data into the table

Insert into table (col1,col2,col3) values ('axiajiajiaoyun')

Insert the queried data into an existing table

INSERT INTO TABLE table_Name

PARTITION (DateKey)

SELECT col1,col2,col3,DateKey FROM otherTable

WHERE DATEKEY IN (2017-02-26)

GROUP BY col1,col2,col3,DateKey

DISTRIBUTE BY DateKey

Store the queried data in the hdfs directory of insert overwrite directory'/ jc_bdcqs/qsy'row format delimitedfields terminated by', 'select * from zqsroomgslistquitHQL to query the common setting items

1) set the calculation fault tolerance rate (to prevent abnormal exit from the program due to errors in the calculation process):

Set mapred.max.map.failures.percent=100

2) limit the number of query output files

Set mapred.reduce.tasks=1

3) controlling the maximum number of reduce will not affect the setting of mapred.reduce.tasks

Set hive.exec.reducers.max = 100

4) how many reducer will be processed in a job? default is 1G.

Set hive.exec.reducers.bytes.per.reducer = 1000000000

Set up dynamic partitions

Set hive.exec.dynamic.partition=true; (can be seen through this statement: set hive.exec.dynamic.partition;), set hive.exec.dynamic.partition.mode=nonstrict; SET hive.exec.max.dynamic.partitions=100000; (if the number of automatic partitions is greater than this parameter, an error will be reported), SET hive.exec.max.dynamic.partitions.pernode=100000; deletes the table

Drop table tb_name

Or empty the table.

Truncate table table_name

Delete partition

ALTER TABLE table_Name DROP PARTITION (Datekey='20190606')

New partition

Alter table tb_name add partition (Datekey = '20190606')

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