<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; ">Robert,<DIV><BR class="khtml-block-placeholder"></DIV><DIV>Thanks for the clarification. I think I got it and agree.</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>BTW, after running your code using persistent objects and adding 5000 users, the total on-disk storage is now 5MB (as compared to 9MB by using non-persistent objects), which concurs with what Ian mentioned yesterday. Anyway, just wanted to point this out for the rest of us.</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV>Thanks again,</DIV><DIV>Daniel</DIV><DIV><BR class="khtml-block-placeholder"></DIV><DIV><DIV><DIV>On Nov 14, 2006, at 3:20 PM, Robert L. Read wrote:</DIV><BR class="Apple-interchange-newline"><BLOCKQUOTE type="cite"><SPAN class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px 0px; color: rgb(0, 0, 0); font-family: Lucida Grande; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; text-align: auto; -khtml-text-decorations-in-effect: none; text-indent: 0px; -apple-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; ">You must either do something like add-to-root, or inherit from persistent-class. In that,<BR>you are correct. Once an object is persisted by either mechanism, it won't be "garbage collected"<BR>from the store; you can kill you lisp image and recreated it and then retrieve the object.<BR>Garbage collection within memory is a separate issue, and less important---you can always<BR>get back to the object.<BR><BR>I feel that I just muddied things by using "add-to-root" here --- creating a persistent<SPAN class="Apple-converted-space"> </SPAN><BR>class is almost always better for a serious application. <SPAN class="Apple-converted-space"> </SPAN><BR></SPAN></BLOCKQUOTE></DIV><BR></DIV></BODY></HTML>