Since fq=role:public will be cached and reused for all the queries that use it, the performance impact will be very small. Once it's cached, there currently won't be a difference between a filter matching 10% of the index vs the whole index since the filtering code is doing a check of a bit in a bitset.
-Yonik Lucene/Solr? http://www.lucidimagination.com On Fri, Feb 20, 2009 at 9:21 PM, Peter Wolanin <peter.wola...@acquia.com> wrote: > We are working on integration with the Drupal CMS, and so are writing > code that carries out operations that might only be relevant for only > a small subset of the sites/indexes that might use the integration > module. In this regard, I'm wondering if adding to the query (using > the dismax or mlt handlers) a fq that matches all documents would have > any impact on performance? I gatehr that there is caching for the fq > matches, but it seems liek that would still incur some overhead, > especially for a large index? > > As a more concrete example, suppose each document has a string field > that names the role of user that is allowed to see the content. e.g. > 'public', 'registered', 'admin'. Most sites have only public content, > but because our code is generic, we might add &fq=role:public to > every query. What would the expected performance effect be compared > to omitting that fq if, for example, we had a way to determine in > advance that all site content matches 'public'. > > Thanks, > > Peter > > -- > Peter M. Wolanin, Ph.D. > Momentum Specialist, Acquia. Inc. > peter.wola...@acquia.com >
