* @return The SQL generated during the execution of the upgrade.
*/
protected String upgrade(VersionUpgrade version, RelationalSchema schema)
{
Upgrade upgrade = new Upgrade(null);
SQLAppender origAppender = m_manager.getSQLAppender();
StringWriter sql = new StringWriter();
upgrade.setMetadata(getMetadata());
upgrade.addVersion(version);
m_manager.setSQLAppender(m_manager.new SQLWriterAppender(sql));