hibernate-devel

[Hibernate] Session.replicate() into IDENTITY table ?

[Darryl L. M. <da...@ne...>]

A few weeks ago I posted on the Forum and Gavin responded, but I'd like 
to know if anyone has taken a look at my response.  Is there another 
purpose that I'm not seeing for Session.replicate() ?  It reads that in 
the case of an IDENTITY table the replicate does not honour its 
documented contract but does a Session.save() instead.

Would it be possible to throw an exception (that does not disrupt 
session state) in the case where replication would not be possible.  Or 
if all exceptions disrupt session state, provide a means where the the 
caller can see if a replicate is possible with a given object, to allow 
programatic checking.

Then provide a Session.replicateOrSave() API call for those users who 
really want the existing behaviour.  This change needs to be made clear 
to allow users to modify their code but in the short term no damage 
would be done as every call to replicate() will result in an exception 
that they will investigate to fix and then they will learn of the change.

At least this leaves the door open in the future as SQL server 
technology improves across the board for enabling this feature 
progressivly and you dont have to work out the exact mechanism for 
enablement right now just have a simple flag per class mapping which by 
default is disabled.

It would be bad of hibernate to tie itself to the lowest common 
demoninator, the feature exists in some SQL servers becauses it 
incredibly useful.

http://forum.hibernate.org/viewtopic.php?t=949574&highlight=


Your thoughts?


-- 
Darryl L. Miles

[Hibernate] Session.replicate() into IDENTITY table ?

[Darryl M. <dar...@ne...>]

A while ago I highlighted a problem with the differences between the 
documented API and what Hibernate actually does and I'm seeking to an 
open discussion about the merits and problems to renaming the current 
#replicate() function to #replicateOrSave() to better identify what it 
actually does.

This is so that a hole can be left open to implement a real #replicate() 
function which makes contact guarantees that the primary key / OID will 
be identical even in IDENTITY tables in the replicated object or 
otherwise it throws an exception.  There should also be a feature 
enquiry function to allow the API programmer to ask the underlying 
Hibernate implementation to verify if a replication on identity table 
will work.  This would account for JDBC driver vendors and versions and 
the realtime SQL database server vendor and version.

http://www.mail-archive.com/hib...@li.../msg05230.html
http://forum.hibernate.org/viewtopic.php?t=949574&highlight=
http://www.hibernate.org/hib_docs/v3/api/org/hibernate/Session.html#replicate(java.lang.Object,%20org.hibernate.ReplicationMode)

RFC

Darryl