[ietf-nntp] OVER message-id

[Charles Lindsey]

In <871xr2yp2a.fsf at windlord.stanford.edu> Russ Allbery <rra at stanford.edu> writes:

>Implementing it is a pain because the user is requesting overview
>information and overview information is not indexed by message ID.  Really
>the only way that you can implement it under most server designs without
>adding another overview index that's almost never used is to retrieve the
>article headers and cobble together the overview on the fly.  That was how
>I was planning on implementing it.

But surely once you have the article, you have the Xref, from which you
have the article number, from which you can look up the overview (no need
to cobble up a fresh copy - in any case, the overview usually includes the
Xref, does it not).

>Andrew's cluster has an additional problem that Xref data isn't actually
>stored in the article, so he simply doesn't have any good way of answering
>an OVER Xref request by message ID.  This is, I believe, somewhat unique
>to his software and is not typical of most server designs, but I could be
>wrong.  I don't have a lot of familiarity with how Xref works across
>servers.

But this I do not understand. If Andrew is prepared to serve up the
complete article (or even just its HEADers) given the message-id, then he
is surely obliged to serve up an Xref header with it (for how else does
the client know how to mark all the crossposted articles as read when he
has read the first one)? So Andrew must possess some mechanism for mapping
the message-id into an Xref header; therefore he should be able to use
that same mechanism to get at the overview.

-- 
Charles H. Lindsey ---------At Home, doing my own thing------------------------
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