Re: A few question regarding schema

["Kurt D. Zeilenga" <Kurt@OpenLDAP.org>]

At 07:09 PM 10/16/2004, Alex Karasulu wrote regarding [Models]:
>1). Most schema entities/objects have the option of being flagged as OBSOLETE.  I say most because Syntax is the only exception to the rule.  
>I'm trying to figure out why this is.  Is it because Syntaxes are always active once defined?  Meaning it makes no sense to mark them as inactive?  If so what happens if a server decides not to support a Syntax and needs to deprecate it before removing the Syntax?

I don't recall any accounts as to why LDAP syntax descriptions
doesn't include an OBSOLETE flag, but I would guess its because
the X.500 doesn't have an OBSOLETE flag that applies to
corresponding ASN.1 data types.

>2). Also as a general rule, most schema objects have a unique OID assigned to them.  The only exception to this rule are matchingRuleUses.  For these entities the numericoid is the OID of the matchingRule they are associated with.  So the question arises: What then is the cardinality between matchingRules and their matchingRuleUse[s]?  I'm guessing that its zero or one matchingRuleUse per matchingRule because you can reference multiple attributes for which the matchingRuleUse would apply to.  Hence it would be redundant to have a many to one relationship.

0-1 to 1.  Note that one values of matchingRuleUses are compared
using objectIdentifierFirstComponentMatch, one cannot have two
values which share the same identifier.

>3). I'm trying to find more information on schema extensions as in:
>
>SyntaxDescription = LPAREN WSP
>       numericoid                 ; object identifier
>       [ SP "DESC" SP qdstring ]  ; description
>/---->extensions WSP RPAREN      ; extensions
>|
>* these extension right here
>
>Could you point me to some detailed information on this subject?

Each description can carry extension information.  The meaning
of any extension information is a topic of the extension
specification (whether that be some future RFC, some implementation
specific document, or whatever).  For example,
   X-BINARY-TRANSFER-REQUIRED 'TRUE'
could be used to tag all syntaxes which require use of ;binary.