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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/