[ http://issues.apache.org/jira/browse/DIRSERVER-800?page=all ]
Emmanuel Lecharny closed DIRSERVER-800.
---------------------------------------
Resolution: Invalid
Pfewww... There is no problem at all. The normalization occurs only for non
indexed values.
> Avoid normalization when searching
> ----------------------------------
>
> Key: DIRSERVER-800
> URL: http://issues.apache.org/jira/browse/DIRSERVER-800
> Project: Directory ApacheDS
> Issue Type: Improvement
> Reporter: Emmanuel Lecharny
> Priority: Critical
> Fix For: 1.5.0
>
>
> Ok, this will be an huge improvment, but also a huge modification. Here is
> the rational :
> - each time we are searching for an entry using an attribute value, we are
> walking a B-Tree doing a comparizon between the given value and the stored
> value. if we have N values stored in the B-Tree, we will do something like
> Log2(N) comparizons.
> - Now, we have to be aware that those comparisons must be done against the
> normalized value of the attribute, and using the assocaited MatchingRule. For
> instance, "Emmanuel", "EMMANUEL" and "emmanuel" are supposed to be the same
> value if there type is CommonName, so we must do an case insensitive
> comparison.
> - a first optimization is already implemented : the incoming value is
> normalized _before_ the search, so we avoid a systematic normalization of the
> incoming attribute
> - but we will normalized each values which have been found into the server
> - again, an optimization is implemented : a cache is used to store normalized
> values, so it happens that sometime, we just get the normalized value from
> the cache.
> - but this cache has a limited size, and as it is a cache, each time we want
> to hit it, a synchronization occurs, which will lead to some concurrent
> access to slowdown.
> At this point, the question is :
> - why don't we store normalized values of attribute instead of simple values?
> The initial (not normalized) value is always present in the entry, so there
> is no need to keep it into the indexes.
> This optimization could have a huge impact if it appears that, under heavy
> loads, the cache synchronization leads to delayed access.
--
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators:
http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira
