Database Reference
In-Depth Information
WARNING
If you plan to have more than one Hive user sharing a Hadoop cluster, you need to make the directories
that Hive uses writable by all users. The following commands will create the directories and set their per-
missions appropriately:
% hadoop fs -mkdir /tmp
% hadoop fs -chmod a+w /tmp
% hadoop fs -mkdir -p /user/hive/warehouse
% hadoop fs -chmod a+w /user/hive/warehouse
If all users are in the same group, then permissions g+w are sufficient on the warehouse directory.
You can change settings from within a session, too, using the SET command. This is use-
ful for changing Hive settings for a particular query. For example, the following command
ensures buckets are populated according to the table definition (see Buckets ) :
hive> SET hive.enforce.bucketing=true;
To see the current value of any property, use SET with just the property name:
hive> SET hive.enforce.bucketing;
hive.enforce.bucketing=true
By itself, SET will list all the properties (and their values) set by Hive. Note that the list
will not include Hadoop defaults, unless they have been explicitly overridden in one of the
ways covered in this section. Use SET -v to list all the properties in the system, includ-
ing Hadoop defaults.
There is a precedence hierarchy to setting properties. In the following list, lower numbers
take precedence over higher numbers:
1. The Hive SET command
2. The command-line -hiveconf option
3. hive-site.xml and the Hadoop site files ( core-site.xml , hdfs-site.xml , mapred-
site.xml , and yarn-site.xml )
4. The Hive defaults and the Hadoop default files ( core-default.xml , hdfs-de-
fault.xml , mapred-default.xml , and yarn-default.xml )
Setting configuration properties for Hadoop is covered in more detail in Which Properties
Can I Set? .
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