>>>>> Hallvard B Furuseth <h.b.furuseth...> writes:
>> * allow any number of (coordinate system, latitude, longitude)
>> triplets to be specified.
>> The last approach seems to be the most flexible. However, I don't
>> know if it's possible to ``tie'' attributes into such a ``triples''
>> with LDAP?
> Like this?
> attribute "coordSys", values ("a", "b", "c")
> attribute "latitude", values ("1", "2", "3")
> attribute "longitude", values ("9", "8", "7")
> Nope... an attribute's values are in an unordered list, so LDAP is
> free to mess that up.
I've suspected that. Thanks.
> Solutions:
> * Make a single attribute with all three values.
> attribute "position", values ("a 1 9", "b 2 8", "c 3 7").
> Syntax Directory String or IA5 String, plus a client-defined syntax
> which clients are responsible for writing and parsing.
Any particular reason not to have a multi-value attribute?
attribute "position", value "a 1 9"
attribute "position", value "b 2 8"
attribute "position", value "c 3 7"
> Or if you really want separate attributes (I'd not do that unless I
> needed to):
> * Create one entry for each coordinate system, and put each variant
> in a separate entry.
> * Create an attribute option range "coordinate-<system name>" so that
> you can create one attribute description set for each coordinate
> system:
> attribute "latitude;coordinate-a", value "1"
> attribute "latitude;coordinate-b", value "2"
> attribute "latitude;coordinate-c", value "3"
> attribute "longitude;coordinate-a", value "9"
> attribute "longitude;coordinate-b", value "8"
> attribute "longitude;coordinate-c", value "7"
IIUC, this will preclude the DSA from maintaining consistency,
as nothing's going to prevent the client from inserting, e. g.,
latitude;coordinate-a but not longitude;coordinate-a?
OTOH, there'd be no way to make multiple (latitude, longitude)
pairs given a single coordinate system.
Given the schema above, would it be possible to make an LDAP
filter for the points lying within a rectangular region (like:
latitude is between 50 and 55, longitude is between 79 and 89)?
> This may require server support for user-defined attribute options
> though. E.g. the "attributeoptions" keyword in OpenLDAP slapd.conf.
ACK. Thanks.
--
FSF associate member #7257
