The database is responsible for transaction isolation, ie it's not
something that OFBiz does. There is configuration in OFBiz for the
desired transaction isolation. For comments and recommendations,
please see the entityengine.xml file where this is configured (just
before the datasource section).
-David
On Jul 8, 2009, at 8:36 PM, sastry mln wrote:
Hi,
In http://www.oracle.com/technology/oramag/oracle/05-nov/o65asktom.html
, Tom Kyte described the differences between Oracle and non-oracle
databases regarding the implementation of isolation levels.
Not sure which non-oracle database he was referring to. but he made
a point that other dbs use "shared read lock" for consistent answers
which has a side effect: "Readers of data will block writers of data"
1) MySQL
I donot know how isolation levels implemented in mysql ..
I found this discussions - http://forums.mysql.com/read.php?97,75190,75584
.
Here the author gave an example of 2 concurrent transactions where
one commits before the other. The results of the first are available
in the second. I do not see anything wrong with that, may be I
missed the point of the author.
2) PostGreSQL
http://www.postgresql.org/docs/8.1/interactive/transaction-iso.html
I read, reread, but could not completely grasp this.
seems it's an esoteric topic for my level of expertise.
My Question is, does ofbiz architecture ensure consistent isolation
behavior across all/popular databses?
Please advise if we need to think through this before choosing a
database for our business needs
regards
Sastry
