Setting the Execution Engine
Consider the following definitions:
| Term | Definition |
|---|---|
| runtime | The execution time of the job. |
| session time | The time from the start of the Hive shell or Beeline until you exit. |
You can change the execution engine during a session (session time), but not while executing
a job in the session (runtime). If you specify the execution engine before starting the job,
it overrides the hive.execution.engine property in the
hive-site.xml file. For example, to specify the execution engine:
hive> set hive.execution.engine=tez;
hive> *perform some query here*If you open another Hive shell or Beeline session, you will not see the setting in the session from before, and you can set the needed properties for every session.
IMPORTANT
Hewlett Packard Enterprise strongly recommends configuring Tez as an execution engine
instead of an MR execution engine. MR execution engine is deprecated in Hive and is not
suitable for use in production environments.If you are currently using the MR execution engine for accessing Hive CLI and HS2, Hive
generates the following warning
message:
Hive-on-MR is deprecated in Hive 2 and may not be available in the future versions. Consider using a different execution engine (i.e. spark, tez) or using Hive 1.X releases.To install and configure Tez as an execution engine for Hive, see Configuring Hive and Tez.