Le 11/12/14 13:21, Michael Ströder a écrit : > Jim Willeke wrote: >> There is an old draft for: >> https://tools.ietf.org/html/draft-ietf-boreham-numsubordinates-01 >> >> And I do think this type of attribute does supply value. Many client we >> work with monitor container counts for stats and compliance. > Not many servers support numSubordinates though. And it's of less value when > search scope and search filter come into play.
The fact is that ApacheDS *does* support numSubordinates. We keep a track of the numbe rof direct children and the track of descendant for every entry. It might be seen as costly, but it's not : as we have to update the full RDN index when we add/remover/move an entry, we just have two counters to increment in each RDN, which is just insignificant compared to the cost of writing those RDN on disk. Now, it's just counting entries in the DIT, it's not really helpful when we have to evaluate the number of entries a search will return. This is where it starts to be complicated, because you really have to filter each entry to see if it matches (and also to check that the ACLs don't forbid the entry to be returned to the client). All in all, counting the number of elements based on any filter/search *will* be a costly operation, you still have to pull the entries from teh backend.
