[Zope-dev] Catalog improvements

[Jeffrey P Shell]

On Tuesday, November 20, 2001, at 03:35  PM, Wolfram Kerber wrote:

> Hi,
>
> i'm currently working on a product that allows to attach relational
> information to zope-objects. It works quite well so far, but to further
> enhance it i need to make some changes to the Catalog. I could perhaps
> implement it as a separate product, but i strongly feel that those 
> changes
> are best applied to the Catalog itself, as they are of general use 
> (i think)
> and involve a lot of changes to the inner workings of the Catalog. In
> particular i need the following:
>
> - named/stored queries
> these are precompiled queries, so they can be executed without 
> parsing and
> are easily cacheable
> i.e. similar to what is implemented in CMFTopic, but stored in the 
> Catalog
> and a bit smarter

There used to be something like this in ZTables/Tabula (a Zope 1.x 
product that was sort of the genesis of the Catalog, for better or 
worse) called 'Hierarchies'.  Hierarchies were actually indexes (I 
think the current Keyword index is descended from the Keyword 
Hierarchy).

I don't know what happened to that code.  If it's not available, 
you could probably achieve the effect that you're looking for here 
with PluginIndexes, which wouldn't require changing the Catalog at 
all.  Just write a "Query Index" that indexes objects that match 
its pre-cooked Query.  This would speed up searching tremendously, 
but you could take a big hit at indexing time if you have many of 
them.

Jeffrey P Shell, jeffrey@cuemedia.com