More questions about MoreLikeThis

[jlist9 <jl...@gmail.com>]

The wiki page (http://wiki.apache.org/solr/MoreLikeThis) says:

mlt.fl: The fields to use for similarity. NOTE: if possible, these
should have a stored TermVector

I didn't set TermVector to true MoreLikeThis with StandardRequestHandler seems
to work fine. The first question is, is TermVector only for
performance optimization?

The second question is, afterI changed the mlt.fl fields from both
indexed and stored
to indexed only, I started to get zero results back. Do mlt.fl fields
always need to
be stored?

Thanks

Re: More questions about MoreLikeThis

[jlist9 <jl...@gmail.com>]

Thanks. That explains it! I'll set termVector to true and give it a try again.

On Mon, May 25, 2009 at 7:41 AM, Koji Sekiguchi <ko...@r.email.ne.jp> wrote:
> MLT uses termVector if it exists for the field. If termVector is not
> available,
> MLT tries to get stored field data. If stored field is not available, MLT
> does nothing for the field as you were seeing.
>
> So mlt.fl fields don't always need to be stored.

Re: More questions about MoreLikeThis

[Koji Sekiguchi <ko...@r.email.ne.jp>]

jlist9 wrote:
> The wiki page (http://wiki.apache.org/solr/MoreLikeThis) says:
>
> mlt.fl: The fields to use for similarity. NOTE: if possible, these
> should have a stored TermVector
>
> I didn't set TermVector to true MoreLikeThis with StandardRequestHandler seems
> to work fine. The first question is, is TermVector only for
> performance optimization?
>
>   
I think yes.

> The second question is, afterI changed the mlt.fl fields from both
> indexed and stored
> to indexed only, I started to get zero results back. Do mlt.fl fields
> always need to
> be stored?
>
> Thanks
>
>   

MLT uses termVector if it exists for the field. If termVector is not 
available,
MLT tries to get stored field data. If stored field is not available, MLT
does nothing for the field as you were seeing.

So mlt.fl fields don't always need to be stored.

Koji