CODEWITHSUNDEEP
solr
Chris Muench
Chris Muench

Reputation: 18338

Solr bf parameters

I was reading through the apache solr module and noticed this:

bf = recip(rord(created),4,90785,90785)^200.0

Could someone explain what this does? It looks like it adds boast to the created field, but i am not sure what all the functions are (recip, rord)

Upvotes: 1

Views: 1065

Answers (1)

cbeer
cbeer

Reputation: 1231

The solr function query methods are documented on the Solr Wiki:

So, the boost query you provided gives a boost to newer documents, using this function that looks like:

(90785/(4*rord(created) + 90785))^200

The newest document:

(90785/(4*1 + 90785))^200 => 0.9912

And the oldest document (assuming 1000 documents):

(90785/(4*1000 + 90785))^200 => 0.0001798

Upvotes: 4

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