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

Switch to Threaded View
Hive >> mail # user >> Dealing with large number of partitions

Copy link to this message
RE: Dealing with large number of partitions
+1 to that. That should help provided you are running hadoop 0.20 ..


From: wd [mailto:[EMAIL PROTECTED]]
Sent: Thursday, June 10, 2010 11:36 PM
Subject: Re: Dealing with large number of partitions
Try set hive.input.format=org.apache.hadoop.hive.ql.io.CombineHiveInputFormat; before you query, this may be help.
2010/6/11 Sammy Yu <[EMAIL PROTECTED]<mailto:[EMAIL PROTECTED]>>
   I am having an issue with a large number of 4000 partitions (each being very small <10k files).  Any queries that I do which involve these partitions take an extremely long time to complete (10+ hours), I was wondering if there was any easy way in hive without having to merge the files improve it's performance.  I can see the map reduce jobs are taking a long time due to the fact that there are so many separated raw data files that need to be read.  I saw that HIVE-1332 dealt with using HAR files for partitioning.  Could this perhaps help performance rather than hurt it, given that the queries will be using all the partitions in the har file?