After adding a partition to an external table in Hive, how can I update/drop it?
You can either copy files into the folder where external partition is located or use
INSERT OVERWRITE TABLE tablename1 PARTITION (partcol1=val1, partcol2=val2...)...
statement.
You can update a Hive partition by, for example:
ALTER TABLE logs PARTITION(year = 2012, month = 12, day = 18)
SET LOCATION 'hdfs://user/darcy/logs/2012/12/18';
This command does not move the old data, nor does it delete the old data. It simply sets the partition to the new location.
To drop a partition, you can do
ALTER TABLE logs DROP IF EXISTS PARTITION(year = 2012, month = 12, day = 18);
Hope it helps!
Alter table table_name drop partition (partition_name);
You may also need to make database containing table active
use [dbname]
otherwise you may get error (even if you specify database i.e. dbname.table )
FAILED Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask. Unable to alter partition. Unable to alter partitions because table or database does not exist.
in addition, you can drop multiple partitions from one statement (Dropping multiple partitions in Impala/Hive).
Extract from above link:
hive> alter table t drop if exists partition (p=1),partition (p=2),partition(p=3);
Dropped the partition p=1
Dropped the partition p=2
Dropped the partition p=3
OK
EDIT 1:
Also, you can drop bulk using a condition sign (>,<,<>), for example:
Alter table t
drop partition (PART_COL>1);