Re: undead articles (Re: nnimap 0.126 released)

[Simon Josefsson <jas@pdc.kth.se>]

Ed L. Cashin <ecashin@coe.uga.edu> writes:

> OK.  You know, I have heard NOV mentioned in many contexts, but I
> really don't know much about it.  
> 
> I have gleaned that NOV is some kind of local map of a foreign source
> of articles that speeds things up a lot but is a bit tricky to keep in
> sync with the foreign article source.  Is that right?

I don't have any references, but as far as I know NOV is a data format
traditionally used to speed up the NNTP XOVER command. The NNTP server
run a cron job to generate a file "overview" which contains, in a
brief format (one line per article) headers of most relevant fields
(Subject, To, Date etc) of articles.

I might be horribly misstaken, but, since overview files were created
by a cron job instead of changed when articles were added/removed from
groups this results in todays horrible stuff in NNTP clients to make
sure the XOVER command returned correct information, and fall back to
fetching article headers with the HEAD command otherwise.

Gnus has adapted the NOV format to use for locally stored mail
folders, and nnimap has done something similar. The term is probably
quite overloaded today, now it's just a format to pass data between
nnimap and Gnus.

If someone knows some references, or have more details, please let us
know.