Re: Fwd: [BUGS] pg_trgm word_similarity inconsistencies or bug

On Mon, Apr 16, 2018 at 07:48:47PM +0300, Liudmila Mantrova wrote:
> Hi everyone,
>
> When translating doc updates, Alexander Lakhin noticed that trigram examples
> were not quite accurate.
> A small patch fixing this issue is attached.

FYI, this has been applied by Teodor Sigaev:

https://git.postgresql.org/pg/commitdiff/9975c128a1d1bd7e7366adf133b21540a2bc2450

---------------------------------------------------------------------------

>
>
> On 03/21/2018 03:35 PM, Teodor Sigaev wrote:
> >Thank you, pushed
> >
> >David Steele wrote:
> >>On 3/6/18 7:04 AM, Teodor Sigaev wrote:
> >>>>I agree with Teodor (upthread, not quoted here) that the documentation
> >>>>could use some editing.
> >>>>
> >>>>I started to do it myself, but quickly realized I have no knowledge of
> >>>>the content.  I'm afraid I would destroy the meaning while updating
> >>>>the
> >>>>grammar.
> >>>>
> >>>>Anyone understand the subject matter well enough to review the
> >>>>documentation?
> >>>
> >>>Liudmila tried to improve docs in Alexander's patchset.
> >>>
> >>>https://www.postgresql.org/message-id/f43b242d-000c-f4c8-cb8b-d37e9752cd93@postgrespro.ru
> >>>
> >>
> >>This looks good to me with a few minor exceptions:
> >>
> >>+   <function>word_similarity(text, text)</function> requires further
> >>+   explanation. Consider the following example:
> >>
> >>Maybe too verbose?  I think "<function>word_similarity(text,
> >>text)</function> requires further explanation." can be removed entirely.
> >>
> >>+   string.  However, this function does not add paddings to the
> >>
> >>"add padding"
> >>
> >>>BTW, adding Liudmila's message to commitfest task
> >>>(https://commitfest.postgresql.org/17/1403/) doesn't work
> >>
> >>Doesn't work for me either.
> >>
> >>Alexander, can you post the final patches to the thread so they show up
> >>in the CF app?
> >>
> >>Thanks,
> >>
> >
>
> --
> Liudmila Mantrova
> Postgres Professional: http://www.postgrespro.com
> The Russian Postgres Company
>

> diff --git a/doc/src/sgml/pgtrgm.sgml b/doc/src/sgml/pgtrgm.sgml
> index 8f39529..be43cdf 100644
> --- a/doc/src/sgml/pgtrgm.sgml
> +++ b/doc/src/sgml/pgtrgm.sgml
> @@ -152,9 +152,9 @@
> </programlisting>
>
> In the first string, the set of trigrams is
> - <literal>{" w"," wo","ord","wor","rd "}</literal>.
> + <literal>{" w"," wo","wor","ord","rd "}</literal>.
> In the second string, the ordered set of trigrams is
> - <literal>{" t"," tw",two,"wo "," w"," wo","wor","ord","rds", ds "}</literal>.
> + <literal>{" t"," tw","two","wo "," w"," wo","wor","ord","rds","ds "}</literal>.
> The most similar extent of an ordered set of trigrams in the second string
> is <literal>{" w"," wo","wor","ord"}</literal>, and the similarity is
> <literal>0.8</literal>.
> @@ -172,7 +172,7 @@
> At the same time, <function>strict_word_similarity(text, text)</function>
> has to select an extent that matches word boundaries. In the example above,
> <function>strict_word_similarity(text, text)</function> would select the
> - extent <literal>{" w"," wo","wor","ord","rds", ds "}</literal>, which
> + extent <literal>{" w"," wo","wor","ord","rds","ds "}</literal>, which
> corresponds to the whole word <literal>'words'</literal>.
>
> <programlisting>

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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