Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
Hive, mail # user - Automating the partition creation process


Copy link to this message
-
Automating the partition creation process
Sadananda Hegde 2013-01-29, 04:05
Hello,

My hive table is partitioned by year, month and day. I have defined it as
external table. The M/R job correctly loads the files into the daily
subfolders. The hdfs files will be loaded to
<hivetable>/year=yyyy/month=mm/day=dd/ folders by the scheduled M/R jobs.
The M/R job has some business logic in determining the values for year,
month and day; so one run might create / load files into multiple sub
-folders (multiple days). I am able to query the tables after adding
partitions using ALTER TABLE ADD PARTITION statement. But how do I automate
the partition creation step? Basically this script needs to identify the
subfolders created by the M/R job and create corresponding ALTER TABLE ADD
PARTITION statements.

For example, say the M/R job loads files into the following 3 sub-folders

/user/hive/warehouse/sales/year=2013/month=1/day=21
/user/hive/warehouse/sales/year=2013/month=1/day=22
/user/hive/warehouse/sales/year=2013/month=1/day=23

Then it should create 3 alter table statements

ALTER TABLE sales ADD PARTITION (year=2013, month=1, day=21);
ALTER TABLE sales ADD PARTITION (year=2013, month=1, day=22);
ALTER TABLE sales ADD PARTITION (year=2013, month=1, day=23);

I thought of changing M/R jobs to load all files into same folder,
then first load the files into non-partitioned table and then to load the
partitioned table from non-partitioned table (using dynamic partition); but
would prefer to avoid that extra step if possible (esp. since data is
already in the correct sub-folders).

Any help would greately be appreciated.

Regards,
Sadu