[Xapian-discuss] FLAG_WILDCARD, add_database and performance

[Oliver Flimm]

Hi,

On Mon, Aug 04, 2008 at 02:01:51AM +0100, Olly Betts wrote:
> On Fri, Aug 01, 2008 at 11:48:57AM +0200, Oliver Flimm wrote:
> > I recently started to combine several (around 140) seperate databases
> > for a single search request with add_database. I use the xapian perl
> > bindings. Additionally I use a match decider to implement facets.
> 
> Xapian version?  Platform?

I tried both Xapian 1.0.5 and 1.0.7 on a 64bit Debian Linux System
(stable/etch). The Debian platform is AMD64 (although we're running on
Intel hardware)

[...]
> A more comparable test would be against the 140 databases merged into
> one.
> 
> But it sounds like something is O(n*n) in the number of databases - that
> shouldn't be necessary that I can see.
> 
> If it's easy to test, see if 100 databases takes about 100 seconds, and
> 70 about 50 seconds.
[...]
> Could you profile to find where the time is spent?  Some tips are here:
> 
> http://trac.xapian.org/wiki/ProfilingXapian
[..] 

Thanks for the hints. I'll try them.

Regards,

Oliver

-- 
Universitaet zu Koeln :: Universitaets- und Stadtbibliothek
IT-Dienste :: Abteilung Universitaetsgesamtkatalog
Universitaetsstr. 33 :: D-50931 Koeln
Tel.: +49 221 470-3330 :: Fax: +49 221 470-5166
flimm at ub.uni-koeln.de :: www.ub.uni-koeln.de