[infinispan-dev] Re: [horizon-dev] serializable isolation level
On 7 Apr 2009, at 19:10, Mircea Markus wrote:
These are 4 isolation defined by ANSI, but as we do not support all
of them, we should not allow users to specify them. What's the
advantage for a user to be able to specify "SERIALIZABLE" and the
system to automatically switch to REPETABLE_READ, i.e. in which
scenario would one want to do that?
Compatibility with JBC. Easy migration of configuration values.
Unless you want to handle the upgrading/downgrading in a migration
script. :-) Which is also OK by me.
[1] states that : "Most DBMSs offer *a number* of /transaction
isolation levels/ which control the degree of locking which occurs
when selecting data" so not all DBMS support all isolation levels.
(e,g, oracle does not support NONE and READ_UNCOMMITTED, DB2 does
not support READ_UNCOMMITTED as well [2]).
--
Manik Surtani
manik(a)jboss.org
Lead, JBoss Cache
http://www.jbosscache.org