Re: 9.6 phrase search distance specification

Thanks,

Ryan Pedela
Datalanche CEO, founder
www.datalanche.com

On Tue, Aug 9, 2016 at 11:58 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Bruce Momjian <bruce(at)momjian(dot)us> writes:
> > Does anyone know why the phrase distance "<3>" was changed from "at most
> > three tokens away" to "exactly three tokens away"?
>
> So that it would correctly support phraseto_tsquery's use of the operator
> to represent omitted words (stopwords) in a phrase.
>
> I think there's probably some use in also providing an operator that does
> "at most this many tokens away", but Oleg/Teodor were evidently less
> excited, because they didn't take the time to do it.
>
> The thread where this change was discussed is
>
> https://www.postgresql.org/message-id/flat/c19fcfec308e6ccd952cdde9e648b5
> 05%40mail.gmail.com
>
> see particularly
>
> https://www.postgresql.org/message-id/11252.1465422251%40sss.pgh.pa.us

I would say that it is worth it to have a "phrase slop" operator (Apache
Lucene terminology). Proximity search is extremely useful for improving
relevance and phrase slop is one of the tools to achieve that.