[Zope-dev] Catalog improvements

[Chris McDonough]

Note that one way to get the effect of "cached queries" is to use a 
TopicIndex, which I believe either Andreas or Tres has implemented.  See 
http://dev.zope.org/Wikis/DevSite/Proposals/TopicIndexes.  I can't find 
the actual source code, though.  Maybe either Tres or Andreas knows 
where it is?

Wolfram Kerber wrote:
> Hi
> 
> No, i wasn't aware of your product :-( , the only one i found was ZOQL by
> Stephan Richter, but that didn't help much. Well, now i have written an
> implementation that reuses some of the code in TextIndex (for parenthesis
> parsing and insertion of a default operator) an then saves the query in RPN
> format (so the Catalog does't need to think that hard when being queried).
> I have taken a look at your product, and i'd say a 'new' Catalog should have
> sort of QueryParser plugins that know how to turn string-queries (as yours)
> or SQL to native Catalog queries ...
> I've also contacted the authors of the two proposals, just wasn't sure
> wether i should start this off, since i have no experience as to how the
> fishbowl works and i'm expected to finish my current project sometime soon.
> 
> 
> Wolfram
> 
> ----- Original Message -----
> From: "Casey Duncan" <c.duncan@nlada.org>
> To: "Wolfram Kerber" <wk@gallileus.de>; <zope-dev@zope.org>
> Sent: Tuesday, November 27, 2001 2:48 PM
> Subject: Re: [Zope-dev] Catalog improvements
> 
> 
> 
>>On Tuesday 20 November 2001 05:35 pm, Wolfram Kerber allegedly 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
>>>
>>>- caching support
>>>
>>>- unions and intersections
>>>sub-queries (i.e. queries that are directed at a certain index) should
>>>
> be
> 
>>>more flexibly combineable
>>>
>>I have some code that implements this in my CatalogQuery product. It
>>
> creates
> 
>>a query object from a string. Presently these are not persistent, but they
>>could easily be made to be to create precompiled queries.
>>
>>code at: http://www.zope.org/Members/Kaivo/CatalogQuery
>>
>>
>>>I searched this mailing-list as well as zope.org to get an idea about
>>>
> what
> 
>>>has already been discussed and requested, and there seems to be some
>>>interest in improving the Catalog. Some people even seem to have worked
>>>
> on
> 
>>>this, perhaps they could give an update on this? Possibly i don't have
>>>
> to
> 
>>>write everything from scratch...
>>>
>>I would be willing to help both in coding and getting the code put into
>>
> the
> 
>>Zope core.
>>
>>
>>>I would have put this into a proposal, but there already are two
>>>
> proposals
> 
>>>that deal with the features i want, one is dedicated to
>>>unions/intersections, the other (TopicIndexes) to performance issues (i
>>>dont't know what's the status of these though, especially the first one
>>>
> is
> 
>>>rather old), and i don't want to hijack them without asking. As so often
>>>
> i
> 
>>>will need to complete my current project first, but would then like to
>>>
> help
> 
>>>in improving the Catalog for a more general use.
>>>
>>Possibly we need to rekindle discussion. I would suggest contacting the
>>authors of those proposals to see how compatible your concepts are wth
>>theirs. Perhaps a new proposal should be drafted with the new ideas and ty
>>them back to the previous ones. If there is redundancy, that can be worked
>>out.
>>
>>
>>>So, if there is interest, i would propose to collect some ideas and
>>>comments about how a better Catalog should look like, how it could be
>>>
> best
> 
>>>implemented and how to organize this effort (with respect to the already
>>>existing proposals).
>>>
>>I am very interested in such a discussion. Let me know what I can do to
>>
> help.
> 
>>/---------------------------------------------------\
>>  Casey Duncan, Sr. Web Developer
>>  National Legal Aid and Defender Association
>>  c.duncan@nlada.org
>>\---------------------------------------------------/
>>
> 
> 
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-- 
Chris McDonough                    Zope Corporation
http://www.zope.org             http://www.zope.com
"Killing hundreds of birds with thousands of stones"