Hi I just have a question about commit and rollback. I'm sure this is probably very database vendor dependent, but I was hopping maybe some of you have an insight...

What happens if....

try
{
begin transaction

// Do 1
// Do 2
// Do 3 <-- DB network disconnected at this point of time.
// Do 4
commit transaction <-- Fails because DB is disconnected
}
catch
{
rollback <-- Fails because DB is disconnected
}

Does hibernate send everything to the DB at commit? (I assume that is when it flushes be default unless you otherwise say so to Hibernate right?)
So if the above is true and commit fails, rollback will obviously fail also cause the DB is still disconnected. But what happens to the begin transaction in the database?

Flushing can happen at other times also (eg. before executing a query). You can change the default by specifying a different FlushMode. See http://docs.jboss.org/hibernate/stable/ ... e-flushing for more information.



The database should of course detect this and rollback anything that has already been sent in that transaction. This assumes that you are using a database that does support transactions. One exception is MySQL with the MyISAM engine.

Thanks I'll look at the flush modes.

I'm using MSSQL 2005

So if I get it the DB will try to rollback even if it doesn't explicitly get a rollback from the application?