Hi This has been fixed recently https://issues.apache.org/jira/browse/HIVE-9529. Merging is triggered in two different ways. INSERT/CTAS can trigger merging of small files and CONCATENATE can trigger merging of small files. The later had a bug which generated MR task instead of TEZ task which was fixed recently. Earlier one will use TEZ task always.
Thanks Prasanth > On Apr 24, 2015, at 12:33 AM, patcharee <patcharee.thong...@uni.no> wrote: > > Hi, > > Is there anyone using hortonworks sandbox 2.2? I am trying to use hive on Tez > on the sandbox. I set the running engine in hive-site.xml to Tez. > > <property> > <name>hive.execution.engine</name> > <value>tez</value> > </property> > > Then I ran the script that alters a table to merge small orc files (alter > table orc_merge5a partition(st=0.8) concatenate;). The merging feature > worked, but Hive does not use Tez, it used MapReduce, so weird! > > Another point, I tried to run the same script on the production cluster which > is on always Tez, the merging feature sometimes worked, sometimes did not. > > I would appreciate any suggestions. > > BR, > Patcharee
