On 1-Jul-08, at 12:25 PM, Guangwei Yuan wrote:
I've noticed some bad performance in faceted browsing, when the
query is
empty (so the MatchAllDocsQuery is used) and there are only filter
queries.
An example of the search url is:
http://hostname:8080/solr/select/?q=&qt=dismax&fq=color:%23000000
One idea is to switch to the StandardRequest in such case, by putting
filters into the query filed, like "q=color:%23000000". But the
downside is
the boost functions for dismax are lost and extra code maintenance.
Any
ideas?
I too have noticed surprisingly poor performance in similar
situations. I've never quite have enough time to track it down, and
at times I have done things like what you suggest (though implemented
using a custom param I can pass to dismax; see http://issues.apache.org/jira/browse/SOLR-407
, though that patch will not apply to current trunk). We've also
discussed giving Solr the ability to detect these situations itself
and apply the appropriate optimizations. It is difficult to come up
with heuristics that always result in faster queries.
It is important to think about how the cache is interacting with
this. Are these cached queries? Filters? What do the cache
statistics read like after re-executing the query multiple times?
cheers,
-Mike
