[Zope-Annce] [ANN] IncrementalSearch[2] -- Bugfix release

Dieter Maurer dieter at handshake.de
Fri Jan 20 14:16:36 EST 2006

I found a bug in "IncrementalSearch[2]" that can cause wrong
results under rare circumstances. One requirement is
a "not" search embedded in an "or" search (but this is not sufficient
to cause the problem).

You find fixed versions at


"IncrementalSearch[2]" is a low level search engine for the 
efficient execution of "and", "or" and "not" queries.

Unlike traditional search engines (like that implemented by Zope's ZCatalog),
it computes hits incrementally (one at a time) and interleaves
hit determination and index lookup. If a query is a quite
specific "and" query (that is the usual case), then "IncrementalSearch"
can result in significantly reduced search times.

I observed gains for "IncrementalSearch2" in an order from about 20 percent
for queries including a large (bushy) "or" query (queries
"IncrementalSearch2" cannot optimize well) up to 95 percent and more
(for pure highly specific "and" queries).


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