From: Charles Lindsey (chl@clw.cs.man.ac.uk)
Date: Thu Mar 02 2000 - 06:33:35 CST
In <874sarxlvt.fsf@erlenstar.demon.co.uk> Andrew Gierth <andrew@erlenstar.demon.co.uk> writes:
>>>>>> "Brad" == Brad Templeton <brad@templetons.com> writes:
> >> 1. the message-id versioning stuff imposes significant constraints
> >> on the design of the history mechanism. The fact that it happens
> >> to be possible with INN's dbz is not a convincing argument.
> Brad> What are those constraints?
>The requirement that given an existing (unversioned) message-id
><foo@bar>, that it be possible to update that (whether by adding a
>duplicate entry or by other means) to refer to a different article.
>(The arrival of article <foo$n=2$xxx@bar> changes the result of doing
>a lookup of <foo@bar>.)
The intended implementation is that you leave the old one in the history
file (Expires will eventually remove it) and add a new one at the end. You
then ensure that dbz always gives you the latest one. I looked at the dbz
in CNEWS, and that seemed easily implementable, so I suppose the same
would go for INN. We discussed this at length some months ago. Is there
any real problem there?
The matter of the Xrefs may be a bit trickier.
> Brad> I've never liked the xref additions, though. I've always felt
> Brad> that replace-in-place is the right answer.
>That does not solve the implementation problems. In particular, the
>requirement to locate the article numbers of the article being
>replaced is still a show-stopper on clustered systems.
When we last discussed this, we ruled out replace-in-place (if someone
figures out a neat way to do it that way, then good luck to him, but we do
not require anything that forces that implementation). The low water mark
was the main show stopper IIRC.
-- Charles H. Lindsey ---------At Home, doing my own thing------------------------ Email: chl@clw.cs.man.ac.uk Web: http://www.cs.man.ac.uk/~chl Voice/Fax: +44 161 437 4506 Snail: 5 Clerewood Ave, CHEADLE, SK8 3JU, U.K. PGP: 2C15F1A9 Fingerprint: 73 6D C2 51 93 A0 01 E7 65 E8 64 7E 14 A4 AB A5