Lennart Regebro wrote at 2007-3-27 11:59 +0200:
>OK, at least this avoids the big intermediate results when searching
>over several indexes. But you still have to get all of the results,
>and sort them before you can return the X first. I have the impression
>that Lucene somehow solves this with their sorting indexes, but I'm
>not sure, and I haven't tried to understand the code.
The ZCatalog, too, can use sorting indexes (and "AdvancedQuery"
which stole the idea from ZCatalog).
However, this approach is only efficient when the sort index size
is small compared to the result size.
If the result size is large, the sorting index can only help you
to get the sorting values quite fast as they are stored compactly
Zope3-dev mailing list