(ITS#3939) min/max function extension to LDAP protocol

[quanah@stanford.edu]

Full_Name: Quanah Gibson-mount
Version: HEAD
OS: Solaris 8
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (171.66.182.82)


It would be particularly useful to have a way to query for the max or min value
of a given attribute from a server.  In particular, this would help sync
replication by allowing a client to quickly determine whether or not its context
CSN is still valid.  This is important, because if a provider shuts down after
setting its context CSN to an entry that has been deleted, or has been modified
twice, since the consumers contectCSN,the consumer has to run a very exhaustive
search to figure out whether or not its contextCSN is still valid.  Having the
min function would immediately let it know whether or not its contextCSN was
still valid.

The max one could be used for things like max uid in db, etc.