Hibernate version:
hibernate-3.2.6.ga

Mapping documents:
<property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>
<property name="hibernate.transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>
<property name="hibernate.current_session_context_class">thread</property>

Code between sessionFactory.openSession() and session.close():
//getSession() will obtain "getCurrentSession()" from the SessionFactory
Criteria crit = getSession().createCriteria(ConfigModule.class);
crit.list();


Full stack trace of any exception that occurs:
org.hibernate.HibernateException: createCriteria is not valid without active transaction

org.hibernate.context.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:297)
$Proxy0.createCriteria(Unknown Source)

Name and version of the database you are using:
Oracle 10g
The generated SQL (show_sql=true):
N/A


I fully understand the above error, and know that if i span a transaction before calling the above code i'll get the list from from database.

But WHY do i need to create a database transaction just for mere SELECT operation.

If i recall it correctly that wasn't needed in the past.

Thanks in advanced.

Well, you actually do need a transaction. A transaction represents a unit of work, and doing a select statement is indeed work.

Many times in the past, the JDBC connection would create the transaction if you didn't do it yourself explicitly. It was also friendly on closes. It's not so freindly anymore.

Hi Mr/Mrs. Cameron

Thanks for taking your time and replied my inquiry regarding this.

Thinking about the resources that a transaction takes on the Database, spanning it for just a SELECT statement, seems wrong to me. Unless someone can debate that.

Again, thanks for your time on reading this post and sharing your thoughts.

-Definition from dictionary.com

Do you need to interact with the database to query records? If not, you don't need a transaction. If you do, you do need a transaction.

:)

When you transact with the database, it must be done within the scope of a transaction. It's pretty much true by definition.

-Cameron McKenzie

-Definition from dictionary.com

Do you need to interact with the database to query records? If not, you don't need a transaction. If you do, you do need a transaction.

:)

When you transact with the database, it must be done within the scope of a transaction. It's pretty much true by definition.

-Cameron McKenzie

Actually most DB's implicitly create a new transaction for each statement when not declared by you (or jdbc, or hibernate), so the performance isn't really a point;
You could actually get better performance when using transaction even on plain selects because if your HQL is actually executed by running multiple SQL statements it will use just one transaction, instead of many...
Additionally you get "repeatable reads", imagine the problem when fetching some fields of your complex entity if the entity was suddenly removed from DB, this is a problem you probably are not ready to manage during a simple select.

Thanks for sharing thoughts, really, really appreciate it.