Re: Gnus' speed

[Karl Kleinpaste <karl@kleinpaste.org>]

David Engster <deng@randomsample.de> writes:
> It depends on the scoring you do. If you score against the whole head or
> even the body, scoring becomes incredibly slow since Gnus has to request
> the head/body, resp.

For those who have reasonable access to your news admins, and if your
server runs INN of any recent vintage, you can do away with most needs
for 'body" search using keywords.

Two aspects:
- The admin can tell INN to include Keywords in overviews simply by
adding it to overview.fmt.  Trivial, harmless, cost-free.
- The admin can enable INN's auto-generated Keywords support.  This eats
some CPU time as articles pass into the system, but not nearly as much
as was once feared.  Basically, the enabling of this causes innd to
analyze articles for most-used words.  Having found the top N of these,
it cobbles up a fake Keywords for the overview without actually changing
the article content.

In either case, for actual original keywords of INN's own keyword
analysis, the Keywords header can be scored by Gnus.  Notice when you do
scoring that there is an 'e' option, for "extra" headers.  There are a
couple variables to set:
- gnus-extra-headers for basic scoring capability, and 
- nnmail-extra-headers, if you want this sort of support for incoming
  mail as well.
E.g.
(setq gnus-extra-headers
      '(Keywords Newsgroups NNTP-Posting-Host To X-Moodwatch))

Other headers besides Keywords can be added to overviews.  My
overview.fmt contains:

Keywords:full
Newsgroups:full
NNTP-Posting-Host:full
Content-Type:full

- Newsgroups is useful, distinct from Xref, because local newsgroup
support may not equal groups to which an article was actually posted.
- NNTP-Posting-Host is useful for "all" scoring-into-oblivion when mass
spam attacks occur.
- Content-Type is useful because I score users based on whether they
bother me with (notably) text/html.