Facet Count number incorrect

[karleq]

Hi,

Have a meta collection running across 10 web collections.
Using facets on the meta based directly on the web collections.

With a !null query - the collections are listed as facets (as they should be) - with a corresponding count (EG: 5500)

But when I click on the facet tickbox - I get actual results of 6500

The number in the collection itself is 6500

How are the facet counts generated? Is there some kind of sampling? Can I change it to be exact?

Using 15.12

Thanks

karl

[TienNguyen]

Hi Karl

Faceted navigation (and other) counts in Funnelback are estimates based on the number of results found when a search query is executed.

The accuracy of the estimates can vary depending on how large the index is and the number of results that are returned.
The counts displayed for category values are estimates that are calculated based on the result set. Because of this, the accuracy will reduce as the search index becomes larger. The numbers may also change when a facet is selected as the estimates are recalculated every time the result set is produced.

The accuracy of the counts can be increased by altering the -daat query processor option to consider more documents before producing the estimate. However, increasing the daat limit will have an impact on the response time of the search results so the decision needs to balance performance against accuracy.
e.g. to increase the daat limit to 100,000 documents add -daat=100000 to the query processor options,

More information on setting DAAT in the Query Processor Option: https://docs.funnelback.com/15.12/more/extra/padre_query_processor_options.html
We also have a knowledgebase article here: https://community.funnelback.com/knowledge-base/implementation/search-interface/faceted-navigation/facet-counts-are-wrong-inconsistent

Regards,
Tien

[karleq]

Thanks Tien - great reply & much appreciated.

I wasn't aware of the knowledgebase - just used to using the docs.funnelback site and would never have realsied the daat config had an impact!

-daat= Range: 0 - 10000000
Specifies the maximum number of full matches for Document-At-A-Time
processing. If set to 0, Term-At-A-Time is used instead (dflt 5000).