I'm using postgres and only the sequence is incremented.

Hibernate version:
3.0.5

Mapping documents:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<!--
Auto-generated mapping file from
the hibernate.org cfg2hbm engine
-->
<class name="com.x.db.maindb.datatransfer.PenDTO" table="pen">
<id name="id" type="integer">
<column name="id" />
<generator class="sequence" >
<param name="sequence">pen_id_seq</param>
</generator>
</id>
<property name="eventTime" type="timestamp">
<column name="event_time" length="8" not-null="true" />
</property>
....
</class>
</hibernate-mapping>
Code between sessionFactory.openSession() and session.close():
s.save(instance);

Full stack trace of any exception that occurs:
n/a

Name and version of the database you are using:
Postgres v 7.4
The generated SQL (show_sql=true):
Hibernate: select nextval ('pen_id_seq')
Debug level Hibernate log excerpt:
Unable to get this working



So, I see that it is indeed updating the sequence but that's all it does, no errors are reported.

Try flushing the session. And please make use of the code tag (it's my pet peeve).

I did that, closed the session _and_ it now uses a transaction object and it works.. thanks.