These are datanucleus paramesters found in hive-default.xml/hive-site.xml. If you change them to the following the metastore schema won't be changed automatically (may be good for preventing accidents).
From: Edward Capriolo [firstname.lastname@example.org]
Sent: Wednesday, December 08, 2010 7:19 AM
Subject: Re: Safe to upgrade to Hive 0.7.0?
On Wed, Dec 8, 2010 at 9:55 AM, Ryan LeCompte wrote:
We would like to experiment with some of the features in the current trunk
(0.7) release. Do you think at this point it's nearing "production-ready" ?
Are there any metastore migration scripts or anything like that before
upgrading to 0.7 from 0.6?
This is hard to say. There are many changes going in around indexing
and authorization. IMHO everyone is taking a lot of care in the design
however, it is still subject to change.
If i were compelled to update I would spin up a new instance into a
new meta-store back end. Then compare the schema of current with 0.6.X
like a diff of 'show create tables'.
Just an FYI. I applied two different hive trunks between 0.5 and 0.6.
and I never needed the update scripts because hive happily updated the
schema for me. After my final upgrade to 0.7.0 I re-ran everything in
the upgrade script just to be safe. Nothing noticeably bad happened to
me during the duration.
I suspect many people will not need to run the update scripts since in
the stock configuration hive seems to auto-update anyway. (Someone
correct me if I am wrong here.) Does anyone know how to specifically
which variable controls this?