Can you recommend a good book, where I can read all such things and understand, how openldap really works? This are all very important things for design and operation.
Your specific issue isn't a commonly encountered one, so probably wouldn't be addressed in any book. However, I'd recommend any book written by Howard on OpenLDAP. Unfortunately, no such thing exists at this time (although there may someday be one).
I have written up documentation on performance tuning OpenLDAP 2.4 that covers most other areas, for my work @ Zimbra, you can find it at:
<http://wiki.zimbra.com/wiki/OpenLDAP_Performance_Tuning_6.0>It's based on you using Zimbra's tools to automatically update the configuration database, but you can easily tweak what it's talking about directly.
--Quanah -- Quanah Gibson-Mount Sr. Member of Technical Staff Zimbra, Inc A Division of VMware, Inc. -------------------- Zimbra :: the leader in open source messaging and collaboration