Simple instructions for using hive

I use:

Hive: Start Hive

The command must end with a semicolon telling Hive to execute the command immediately, not case sensitive

show tables; see what tables are available

DESC TableName; See which columns are in the table

Write SQL command

Use UDW;

Select user_id,action_id

from Udw_ml_user_action

where partition_date>=20150410

Distribute by user_id

Sort by user_id,action_id

Limit ten;

Execute sql:hive-f Test.sql

Results of Export search: redirected to files in other formats: Hive-f *.sql >a.txt

II Some commands for querying data

ORDER BY: Full ordering, but only through a reducer, large data sets are less efficient

Sort by: Produces a sort file for each reducer

Distribute by: Controls which reducer a particular line should go to; For example, distribute by year guarantees that all rows with the same years end up in the same reducer partition

GROUP BY: Group Rows by field

Simple instructions for using hive