Showing posts with label insert overwrite. Show all posts
Showing posts with label insert overwrite. Show all posts

Tuesday, 18 November 2014

Update Statement In Hive For Large Tables


Hive Version used - hive-0.12.0

In Previous Blog  we have seen creating and loading data into partition table.
Now we will try to update one record using INSERT statement as hive doesnt support UPDATE command. In newer version of hive, UPDATE command will be added.

 We will see an example for updating Salary of employee id 19 to 50,000

INSERT INTO TABLE Unm_Parti PARTITION (Department = 'A') SELECT employeeid,firstname,designation, CASE WHEN employeeid=19 THEN 50000 ELSE salary END AS salary FROM Unm_Parti Where employeeid=19;
Using the above command your hive record get updated.

From hive-0.14 onwards UPDATE is available.
How to use CURD operations in hive-0.14.0