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From Erick Erickson <>
Subject Re: Index time boosts, payloads, and long query strings
Date Sat, 21 Nov 2009 20:32:56 GMT
I'll take a whack at index .vs. query boosting. They are expressing very
different concepts. Let's claim we're interested in boosting the title

Index time boosting is expressing "this document's title is X more important

than a normal document title". It doesn't matter *what* the title is,
any query that matches on anything in this document's title will give this
document a boost. I might use this to give preferential treatment to all
encyclopedia entries or something.

Query time boosting, like "title:solr^4.0" expresses "Any document with solr
it's title is more important than documents without solr in the title". This
only makes sense if you have other clauses that might cause a document
solr  the title to match......

Since they are doing different things, efficiency isn't really relevant.


On Sat, Nov 21, 2009 at 2:13 AM, Girish Redekar

> Hi ,
> I'm relatively new to Solr/Lucene, and am using Solr (and not lucene
> directly) primarily because I can use it without writing java code (rest of
> my project is python coded).
> My application has the following requirements:
> (a) ability to search over multiple fields, each with different weight
> (b) If possible, I'd like to have the ability to add extra/diminished
> weights to particular tokens within a field
> (c) My query strings have large lengths (50-100 words)
> (d) My index is 500K+  documents
> 1) The way to (a) is field boosting (right?). My question is: Is all field
> boosting done at query time? Even if I give index time boosts to fields? Is
> there a performance advantage in boosting fields at index time vs at using
> something like fieldname:querystring^boost.
> 2) From what I've read, it seems that I can do (b) using payloads. However,
> as this link (
> )
> suggests, I will have to write a payload aware Query Parser. Wanted to
> confirm if this is indeed the case - or is there a out-of-box way to
> implement payloads (am using Solr1.4)
> 3) For my project, the user fills multiple text boxes (for each query). I
> combine these into a single query (with different treatment for contents of
> each text box). Consequently, my query looks something like (fieldname1:
> queryterm1 queryterm2^2.0 queryterm3^3.0 +queryterm4)^1.0  Are there any
> guidelines for improving performance of such a system (sorry, this bit is
> vague)
> Any help with this will be great !
> Girish Redekar

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