I understand that with 3.1 it's no longer possible to create tables
while cursors are open on any table in the database. The source suggests
that this is due entirely to the mechanics of auto-vacuum mode:
http://www.srcdoc.com/sqlite_3.2.2/btree_8c-source.html#l04716. So I'm
curious as to why this restriction is applied indiscriminately, even if
auto-vacuum mode is not enabled. Is there another reason for it?