<html><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div><blockquote type="cite"><div><font class="Apple-style-span" color="#000000"><br></font>I've also wondered what parts of syncing run inside a<br>transaction. ASDF compilation prevents async interruptions<br>at least but of course another thread could be in the middle<br>of some op when the sync happens.<br><br> Leslie<br></div></blockquote></div><br><div>Synchronization in the sense of on-disk instance updates are all degree-2 transactional as I recall. However the rub is the caching of class schema references in the slots of persistent-metaclasses instances. The transaction system doesn't help with side effects to non-DB objects. Generally, schema updates are done by a single thread, but they may interfere with other threads that, for instance, are doing a lazy schema update on an access to a non-updated instance.</div><div><br></div><div>Ian </div></body></html>