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Re: Index for objectclass does not work...
Steeg Carson wrote:
2011/1/6 Howard Chu<firstname.lastname@example.org>:
Steeg Carson wrote:
2011/1/4 Quanah Gibson-Mount<email@example.com>:
--On Tuesday, January 04, 2011 1:43 AM +0100 Steeg Carson
I simulate this on my database just right now:
I suggest you read:
to understand how indices and their slots work.
As I now understand, the entire index for one attribute (e.g.
objectClass) is "split" in several indexes. They holds for each
path/node (resp. DN, but not leaf) an separate index for this
attribute with all "hits" for his subtree (and for onelevel too).
No. Only the dn2id table maintains any notion of nodes and subtrees. All
indices are global to the database and have no notion of scope.
But what does mean (from
"Ordinarily at each level of the tree we keep an index tallying all of
the children beneath that point. In back-bdb this index is used for
subtree searches and for onelevel searches."
So if I do a search, I'll get every time ALL results (ID's) from the
index for the searched value. If my search uses additionally a
searchbase the slapd takes all ID's and lookup in id2entry.bdb to get
the DN for the ID and compare?
The search scope provides a set of candidates, consisting of every entry
within that scope of the tree. An index lookup provides a set of candidates,
consisting of every entry in the DB that matches the index. The intersection
of these sets forms the set of candidate entries that must be examined in depth.
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.
There is no book on the internals of back-bdb or hdb. The source code is there
for anyone to read. If you want to learn more, there are also extensive
discussions on the design approaches and tradeoffs in the archives of the
openldap-devel mailing list. For the most part, these discussions have only
ever been of interest or relevance to other OpenLDAP developers.
-- Howard Chu
CTO, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc/
Chief Architect, OpenLDAP http://www.openldap.org/project/