wood burning stoves 2.0*
The moose likes EJB and other Java EE Technologies and the fly likes How EJB handles DB Locking ? Big Moose Saloon
  Search | Java FAQ | Recent Topics | Flagged Topics | Hot Topics | Zero Replies
Register / Login

Win a copy of EJB 3 in Action this week in the EJB and other Java EE Technologies forum!
JavaRanch » Java Forums » Java » EJB and other Java EE Technologies
Bookmark "How EJB handles DB Locking ?" Watch "How EJB handles DB Locking ?" New topic

How EJB handles DB Locking ?

subramanian annamalai

Joined: Mar 06, 2005
Posts: 22

How EJB Handles Database Locking ? like for example Optimistic locking.

Please explain me.

Valentin Tanase
Ranch Hand

Joined: Feb 17, 2005
Posts: 704
Hi Subramanian,

Data concurrency is a complex subject and usually it is achieved through specific database technologies and transaction isolation levels. However there are other vendor specific strategies. WebLogic for example has four concurrency strategies:
  • Exclusive
  • Database
  • Read-only
  • Optimistic

  • The default is the database concurrency strategy, which will delegate the responsibility of data locking to the underlying database system.
    The optimistic strategy enforces concurrency using the classic client/server approach of ensuring that the data have not been changed by other clients during the transaction. This of course works only with CMP and for each update the container will issue a query like this:


    I think, therefore I exist -- Rene Descartes
    I agree. Here's the link: http://aspose.com/file-tools
    subject: How EJB handles DB Locking ?
    Similar Threads
    Doubt in Thread Ques
    Love the code barn! How 'bout some more?
    Distrubuted EJB
    Confused about Locking
    About locking and RandomAccessFile