Listing names, file names, and version numbers

[Paul Hoffman / IMC <phoffman@xxxxxxx>]

Sorry about taking so long to get to this. I missed Chris' request that we
start in without him.

After the discussion in DC, I propose the following:

- Each schema has an internal name that is chosen by the schema author. It
must be unique, and the vetting group will verify this. People searching
the listing service will definitely be able to search on this.

- The file names will look like an OID. This works well for the only type
currently defined (LDAP). If other types cannot use names that are in
number-period-number-period... format, we can come up with an alternate
filenaming scheme for them that will use the same numbers as the "base"
numbers.

- The OID will look like:

     base . sequence . listversion . type

sequence = 0*<DIGIT>; unique number for the schema

listversion = 0*<DIGIT>; version of this listing (0 is special)

type = 0*<DIGIT>; (1 for ldap, 2 for whois++, and so on)

(Note that I got rid of "typeversion" from my previous proposal. At DC, we
thought that any change to a type within a particular version of a listing
should cause the listing version number to change.)

Listversion is initialized at 1 for the first submission of a schema.
Updates to either a schema or to an individual type cause the version
number to be incremented by 1.

When requesting a schema from the listing service, using a listversion of 0
indicates "the highest current listversion number", meaning the most recent
version.

When requesting the metadata for a schema, no type is given. This means
that the OID for the metadata is "base.sequence.listversion" 

Retrieval would be as follows:
base.12.4:       returns the metadata for version 4 of schema 12
base.12.0:       returns the metadata for the latest version of schema 12
base.12.4.1:   returns the schema listing for the ldap instantiation of
                    version 4 of schema 12
base:            error
base.12:         error

- An alternaive listname would be:

file-name = "schema-" sequence "-v" listversion "-" typename
			  
For instance, "schema-12-v4-ldap". The metadata would be called
"schema-12-v4-metadata".

I am not particularly fond of these human-readable names. I think that
calling the schema "schema.12.4.1" is actually more useful than calling it
"schema-12-v4-ldap" because then you have the OID immediately. That is,
having two external names (a file name and an OID) is worse than having one.

All comments are welcome.


--Paul Hoffman, Director
--Internet Mail Consortium