[HIVE-1841] datanucleus.fixedDatastore should be true in hive-default.xml

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.6.0
• Fix Version/s: 2.0.0
• Component/s: Configuration, Metastore
• Hadoop Flags: Incompatible change
• Assignee: Ashutosh Chauhan
• Reporter: Edward Capriolo
• Created: 08/Dec/10 17:26
• Updated: 24/Jul/16 06:46
• Resolved: 15/Nov/15 04:45

Description

Two datanucleus variables:

<property>
 <name>datanucleus.autoCreateSchema</name>
 <value>false</value>
</property>

<property>
 <name>datanucleus.fixedDatastore</name>
 <value>true</value>
</property>

are dangerous. We do want the schema to auto-create itself, but we do not want the schema to auto update itself.

Someone might accidentally point a trunk at the wrong meta-store and unknowingly update. I believe we should set this to false and possibly trap exceptions stemming from hive wanting to do any update. This way someone has to actively acknowledge the update, by setting this to true and then starting up hive, or leaving it false, removing schema modifies for the user that hive usages, and doing all the time and doing the updates by hand.

Issue Links

• depends upon: HIVE-1530 Include hive-default.xml and hive-log4j.properties in hive-common JAR
• is duplicated by: HIVE-7129 Change datanucleus.fixedDatastore config to true
• is related to: HIVE-6113 Upgrade DataNucleus [was: Unable to instantiate org.apache.hadoop.hive.metastore.HiveMetaStoreClient]
• relates to: HIVE-14152 datanucleus.autoStartMechanismMode should set to 'Ignored' to allow rolling downgrade
• relates to: HIVE-14322 Postgres db issues after Datanucleus 4.x upgrade
• relates to: HIVE-3764 Support metastore version consistency check