Quoting Mike Taylor <mike indexdata.com>:
> Edward C. Zimmermann writes:
> > In Zebra this may be the case (I don't know) but
"F", "S" or "B"
> > don't have to be record subsets. The
"Brief" record (as other
> > "synthetic" elements) may indeed contain
extracorporeal material.
>
> A target must always recognize the character string
> "F" as an element set name to mean
"full"; when it is
> applied to an abstract database record, it results in
> the same abstract database record (i.e. a null
> transformation).
The character string "F" needs to return a record
with the "semantics"
full but what are the semantics for "full"? It
need not ever be the
record as entered into the system. One must also accept that
from the
point of view of a target an abstract database record for a
given origin
may be something other than its own internal
"record", to whatever
extent the underlying server even has records. In the SRU
list, I think,
you have followed that I'm starting to view what records are
on the basis
of queries. In my Shakespeare example the search query
defines the semantic
unit of record which can be LINE, SPEECH, ACT or.. and not
just play or
something preset and poured in concrete but within a model
of Ancestors
and their Descendants. This is getting beyond the scope of
this list but
what is clear is that "Record" as a retrieval unit
is an abstraction.
Since the records we're talking about are abstract and we
then apply something
to mean "Full" what do we have? What we don't have
is everyone meaning the same
thing!
>
> A target must always recognize the character string
> "B" as an element set name to mean
"brief" record.
> This standard does not define the meaning of
"brief."
> Unless the origin knows the target's definition of
> "brief" for a given schema, it should not
assume that
> any particular elements are included.
What constitutes a Brief ("B") or Summary
("S") "element" of a record
is intentionally not specified. Its not even specified as an
"element"
of the record but as a synthetic element name assigned to a
particular
stream of characters chosen to be called the Brief or
Summary elements.
>
> -- ANSI/NISO Z39.50-1995, section 3.6 (Composition
> Specification), subsection 3.6.2 (Comp-spec
Omitted).
>
> Seems pretty explicit to me that the element-set names
"F" and "B"
> represent "full" and "brief",
whatever those two descriptions mean;
> and also the "F" really is a full record
("the same abstract database
No. You are reading into the standard. There are some
profiles that have
defined the set of elements in the target and what full
needs to contain
(all these) but that's NOT what the standard says in
general. It says
"Full", whatever "full" may mean... and
in many implementations it indeed
means different things.
As you well know Z39.50 has since the first version gone
beyond the card
catalog paradigm to be a much more abstract protocol not
just about OPACs.
The background to Brief was, you call, to convey a short bit
of information
("Brief") about what a record (as in
"F") would deliver. It got abstracted.
There are some devious uses.
About a dozen years ago (my how time flies) in a project for
the EU Council
we had records authored in their own language (French with
French, German
with German etc.) but had multiple translations for Brief.
> record"). I suppose the wording of the standard
leaves open the
> possibility that "B" could contain
"extracorporeal material", but
> since that would be material not in "F" it
would be rather perverse.
You'd not be the first to call it so 
> > The element "F" is really also
misleading since there is nothing
> > about "F" to say that its really the
full-record (or even that
> > there is a "full record") but its what's
been (nearly arbitrarily
> > or set forth in a profile) decided to be the
"F" render of the
> > record in the specified syntax.
>
> I don't see how to sqare that interpretation with the
words of the
> standard.
Lets not talk about the standard here (we have others lists
for that and
can get others to join the fun) but let's talk about real
world targets.
Not all targets (mine for instance) will give anyone
everything when then
asked for "F". I'll even give different things
(even different takes
on the semantics for "Full") with different record
syntaxes.
--
--
Edward C. Zimmermann, Basis Systeme netzwerk, Munich
Office Leo (R&D):
Leopoldstrasse 53-55, D-80802 Munich,
Federal Republic of Germany
http://www.nonmonotonic.n
et
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