[ZODB-Dev] Re: Community opinion about search+filter

Dieter Maurer dieter at handshake.de
Mon Mar 19 19:26:14 EDT 2007

Martijn Faassen wrote at 2007-3-15 18:04 +0100:
> ...
>It would be very nice if someone could look into expanding hurry.query 
>and/or the catalog to support these cases. It would be interesting to 
>look at what Dieter Maurer has done with AdvancedQuery in Zope 2 in this 
>regard as well.

AdvancedQuery performs the query (without considering any sorting)
and then tries to use known sortedness properties of the sort index[es]
to sort the result set lazily.

It can gain significantly only when the size of the sort index
is considerably smaller than the result set (this usually is the
case for narrow (e.g. classification) indexes and not the case
for broad (e.g. date) indexes).

In the (very) special case that the ranking criteria only
depends on the objects and not on the query (Google's ranking
by document interconnectivity might be an example; rank by
recency is another one),
the object rank can be incorporated directly in the indexes
and then "IncrementalSearch" may maximally exploit lazy (incremental)
access to the result set.


More information about the ZODB-Dev mailing list