(Partial) result of LIST OVERVIEW.FMT?

[Julien ÉLIE]

Hi,

   The information stored in the overview database may change over time.
   If the database records the content or absence of a given field (that
   is, a header or metadata item) for all articles, it is said to be
   "consistent" for that field.  If it records the content of a header
   for some articles but not for others that nevertheless included that
   header, or if it records a metadata item for some articles but not
   for others to which that item applies, it is said to be
   "inconsistent" for that field.

   The LIST OVERVIEW.FMT command SHOULD list all the fields for which
   the database is consistent at that moment.  It MAY omit such fields
   (for example, if it is not known whether the database is consistent
   or inconsistent).  It MUST NOT include fields for which the database
   is inconsistent or that are not stored in the database.  Therefore,
   if a header appears in the LIST OVERVIEW.FMT output but not in the
   OVER output for a given article, that header does not appear in the
   article (similarly for metadata items).

   These rules assume that the fields being stored in the database
   remain constant for long periods of time, and therefore the database
   will be consistent.  When the set of fields to be stored is changed,
   it will be inconsistent until either the database is rebuilt or the
   only articles remaining are those received since the change.
   Therefore, the output from LIST OVERVIEW.FMT needs to be altered
   twice.  Firstly, before any fields stop being stored they MUST be
   removed from the output; then, when the database is once more known
   to be consistent, the new fields SHOULD be added to the output.


Does anyone know how it can be handled?

Do we have to save somewhere (in <pathoverview>?) the contents and
the time of the last modification of overview.fmt and compare it
at each reload?  Then, when LIST OVERVIEW.FMT is called, we have
to compare a lot of things and a few issues can arise.  For instance if
we have two (or more!) consecutive modifications of overview.fmt with
no posted messages between both of them (or we can even imagine that
they are all cancelled some time after), etc.
I do not see well how I can be sure that the database is consistent
for *all* the articles...


Well, the SHOULD seems difficult to satisfy...


Nevertheless, the MUST NOT is easy :)
So my question is:  does somebody complain if I hardcode the result
of LIST OVERVIEW.FMT with these seven (mandatory) fields?

LIST OVERVIEW.FMT
215 Order of fields in overview database.
Subject:
From:
Date:
Message-ID:
References:
Bytes:
Lines:
.


Too bad for "Xref:full" which disappears...  But I do not see how we
can be sure this field is consistent.  Any idea?
(Anyway, it will still be in the result of OVER/XOVER.)

-- 
Julien ÉLIE

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