http://www.nabble.com/hibernate3%3Ahbm2ddl-tf3334873s2369.html

Steps to reproduce:

2.0-m3 struts-basic-archetype

1) Create a new model class and add it to the hibernate.cfg.xml.
2) Run mvn compile hibernate3:hbm2ddl
3) Modify the model class (add a new property or relationship, or even rename something)
4) Repeat step2....your schema table should not have changed. You should get a MVN error to the effect:

create table spectrum_query (id bigint not null auto_increment, scanNumber varchar(255) not null unique, search_summary_id bigint, primary key (id)) type=InnoDB;
[ERROR] SchemaExport - Unsuccessful: create table spectrum_query (id bigint not null auto_increment, scanNumber varchar(255) not null unique, search_summary_id bigint, primary key (id)) type=InnoDB
[ERROR] SchemaExport - Table 'spectrum_query' already exists