oldLogInstant = this.page.getLastLogInstant();
oldversion = this.page.getPageVersion();
SanityManager.ASSERT(oldversion == this.getPageVersion());
SanityManager.ASSERT(oldLogInstant == null || instant == null
|| oldLogInstant.lessThan(instant));
}
// if this is called during runtime rollback, PageOp.generateUndo found
// the page and have it latched there.
// if this is called during recovery redo, this.needsRedo found the page and