public SchemaValidator(Configuration cfg) throws HibernateException 
{
		this( cfg, cfg.getProperties() );
}

 public SchemaValidator(Configuration cfg,
    Properties connectionProperties) throws HibernateException 
{
		this.configuration = cfg;
		dialect = Dialect.getDialect( connectionProperties );
		Properties props = new Properties();
		props.putAll( dialect.getDefaultProperties() );
		props.putAll( connectionProperties );
		connectionHelper = new ManagedProviderConnectionHelper( props );
}

 public SchemaValidator(Configuration cfg,
    Settings settings) throws HibernateException 
{
		this.configuration = cfg;
		dialect = settings.getDialect();
		connectionHelper = new SuppliedConnectionProviderConnectionHelper(
				settings.getConnectionProvider()
		);
}

 public static  void main(String[] args) 
{
		try {
			Configuration cfg = new Configuration();
			String propFile = null;
			for ( int i = 0; i <  args.length; i++ ) {
				if ( args[i].startsWith( "--" ) ) {
					if ( args[i].startsWith( "--properties=" ) ) {
						propFile = args[i].substring( 13 );
					}
					else if ( args[i].startsWith( "--config=" ) ) {
						cfg.configure( args[i].substring( 9 ) );
					}
					else if ( args[i].startsWith( "--naming=" ) ) {
						cfg.setNamingStrategy(
								( NamingStrategy ) ReflectHelper.classForName( args[i].substring( 9 ) ).newInstance()
						);
					}
				}
				else {
					cfg.addFile( args[i] );
				}
			}
			if ( propFile != null ) {
				Properties props = new Properties();
				props.putAll( cfg.getProperties() );
				props.load( new FileInputStream( propFile ) );
				cfg.setProperties( props );
			}
			new SchemaValidator( cfg ).validate();
		}
		catch ( Exception e ) {
			log.error( "Error running schema update", e );
			e.printStackTrace();
		}
}

 public  void validate() 
{
		log.info( "Running schema validator" );
		Connection connection = null;
		try {
			DatabaseMetadata meta;
			try {
				log.info( "fetching database metadata" );
				connectionHelper.prepare( false );
				connection = connectionHelper.getConnection();
				meta = new DatabaseMetadata( connection, dialect, false );
			}
			catch ( SQLException sqle ) {
				log.error( "could not get database metadata", sqle );
				throw sqle;
			}
			configuration.validateSchema( dialect, meta );
		}
		catch ( SQLException e ) {
			log.error( "could not complete schema validation", e );
		}
		finally {
			try {
				connectionHelper.release();
			}
			catch ( Exception e ) {
				log.error( "Error closing connection", e );
			}
		}
}

Perform the validations.