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Re: order of attribute values

Forest Hill wrote:
In current implementations OpenLDAP (2.2.x & 2.3.x) what's the stand of guaranteeing order of attribute values? I've always been under the assumption that there was no guarantee of preservation of attribute value order. Can someone clarify this?
The X.500 and LDAP specifications explicitly state that order is not preserved and must not be relied on. In OpenLDAP 2.3 we've implemented a number of extensions that allow the order of values in multi-valued attributes to be preserved. The first is the X-ORDERED 'VALUES' extension which may be specified in an attribute's schema definition. I have discussed this extension at length in earlier posts to this list, check the archives for more details.

Also in 2.3 is the valsort overlay which allows multi-valued attribute values to be ordered dynamically based on simple sorting rules (alpha / numeric ascending / descending, weighted). See the slapo-valsort(5) manpage for more details.

RFCs for both of these features will be coming out in the near future. I don't know that they need to progress to anything more than Informational status, but we'll see.

 -- Howard Chu
 Chief Architect, Symas Corp.  http://www.symas.com
 Director, Highland Sun        http://highlandsun.com/hyc
 OpenLDAP Core Team            http://www.openldap.org/project/