Rank newbie question here.
Why are simple queries in the beginning examples always wrapped in a transaction. That seems wasteful. I could understand transactions for updates/inserts but queires? what's up with that?

for example:

I don't know. I sure as hell don't wrap my hibernate queries in transactions though.

So you are running your queries with dozens of short auto-committed transactions. Why exactly is this better than one? Note that if you say something like "it is faster" or "it scales better" or "it makes my code cleaner" you actually have to prove it.

I was speaking as a general observation of my code.

I have many transactions, just don't usually use them when I'm calling a one-time use query that is kinda by itself.

That might be the answer to my question. What "short auto committed transactions"? Simply doing a select causes hibernate to create a short auto committed transaction"?

If that is true then if you do a single select you don't need to include the beginTransaction call since it's auto but if you do more than one select and you want them in the same tranactions (but how do you roll back a select?) then you use your transaction facade class.

I may be getting more confused.

Of course, because there is simply no way to talk to a database "outside" or "wihtout" a database transaction at the lower level. The JDBC connection Hibernate obtains will be in whatever mode it is by default. (Actually, the behavior is pretty much undefined if you do not enable auto commit handling in the Hibernate configuration, in that case.)

And yes, the auto-commit mode is evil and confusing.

Just use these Session/transaction handling patterns for all units of work and do not use auto-commit mode.

http://hibernate.org/42.html

I have explained this again in much much more detail (it is not really a Hibernate thing) in the book Java Persistence with Hibernate, which you can subscribe to at http://www.manning.com

Thanks for the reply and clarification. This was inadequately addressed in the first edition books I've read. I assume you are plugging the new edition because you clarified this in print.

on the page you cited:
... in fact, every SQL statement, be it queries or DML, has to execute inside a database transaction. There can be no communication with a database outside of a database transaction.

about auto commit. Hibernate automatically turns off autocommit?
That would make sense with the preceding paragraph.