pcache + LDAP_NO_ATTRS

[Mike Malsman <zep-openldap-software@ni.enate.org>]

I am using OpenLDAP 2.3.33.  I run a slapd service using the pcache  
overlay, which in turn queries another instance of slapd by means of  
'database ldap'.  It seems to work nicely for my simple use.  I can  
verify that query results are cached if the requested attribute  
matches that of the "proxyattrset" directive.

However, I have a software which specifies LDAP_NO_ATTRS to the  
attributes parameter of ldap_search_st(), as the software is  
interested only in the presence of results, not their content.  Is it  
possible to instruct the pcache overlay, via "proxyattrset" or any  
combination of other directives, to cache the results of such queries?

I have unsuccessfully attempted to define "proxyattrset 0", simply  
omitting the attribute set.  slapd starts fine, but does not seem to  
cache my queries.  It is unclear to me how slapd interprets this  
configuration.

I've failed to find any relevant information in the list archives or  
google.  Am I asking the wrong question?  Is this simply an unnatural  
use of the pcache overlay?

Ciao,
 -Mike