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relative speed of writes

  What is the relative complexity of reads and writes in
  OpenLDAP? Are modifications as expensive as creations? I'm
  aware that writes are not as cheap as reads, and anecdotally
  I've seen figures like ten-to-one -- the usual justification
  being that writes force the lookup tree to be rebalanced.
  Which lookup tree? The articles I've read (their URL escapes
  me at the moment) don't really say, but I assume it's the DN
  lookup tree.

  I'd like to know:
 o  How does the complexity of creation vary? Maybe the tree is
    rebalanced only once in awhile.
 o  Do attribute modifications have the same complexity as
    creation? Probably not, if the issue is rebalancing the DN
    lookup tree.

  I will be able to ask more intelligent questions in the coming
  month, when I put together benchmarks and actually learn the
  OpenLDAP API -- so I have not asked for any ratios, for
  example (comparing number of `ldap_search_ext()` requests to
  number of `ldap_mod_ext()` requests is disingenuous, since the
  latter gets a DN to start with and the former does not.)

  At this point, I'm working out a proposal to propose another
  proposal for using LDAP for horizontally scalable storage of
  small records -- I need to be able to say something about
  write performance, but I'm not able to put work into the
  benchmarking yet.