[Zope-dev] Re: More resilient indexes

[Roché Compaan]

On Tue, 2007-09-18 at 20:01 +0200, Dieter Maurer wrote:
> Roché Compaan wrote at 2007-9-18 08:55 +0200:
> > ...
> >Sorry if I was unclear but what I'm really asking is if it is possible
> >to improve the conflict handling of the current indexes that we have in
> >Zope. I am also asking if concurrent indexing in the ZODB is a realistic
> >goal.
> 
> I have implemented "Conflict Reduced Indexes".
> 
> They essentially work as follows:
> 
>    Standard indexes use for efficiency reasons a complex
>    dance with a quite high conflict potential:
>    The document list for a term can have 3 implementation
>      missing, represented as an integer, represented as an IITreeSet.
> 
>    Whenever the implentation type changes, a conflict will occur
>    when a concurrent request accesses the same document list.
> 
>    The conflict reduced indexes use only 2 implementation types:
>      missing and IITreeSet and once, the list used an IITreeSet,
>      it remains this way.
>    This can leverage the conflict resolution build in "OOBTree"
>    and "IITreeSet" quite well.
> 
> Nevertheless, it turned out that these separate indexes were
> not worth the efford (meanwhile, they have been replaced by
> "ManagableIndex").

Thanks for your feedback. I refactored things a little bit so that I
don't require immediate indexing which makes QueueCatalog a good
solution.

-- 
Roché Compaan
Upfront Systems                   http://www.upfrontsystems.co.za