From: Tom Lane <tgl@sss.pgh.pa.us>
To: Laurenz Albe <laurenz.albe@cybertec.at>
cc: pperalta@gmail.com, pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #18149: Incorrect lexeme for english token "proxy"
In-reply-to: <25d0bf34e0f7e0d9f3455e1b7adaf5a5aee810e1.camel@cybertec.at>
References: <18149-936d14e6fc76ca61@postgresql.org>
 <25d0bf34e0f7e0d9f3455e1b7adaf5a5aee810e1.camel@cybertec.at>
Comments: In-reply-to Laurenz Albe <laurenz.albe@cybertec.at>
	message dated "Sat, 07 Oct 2023 14:49:21 +0200"
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Date: Sat, 07 Oct 2023 10:18:56 -0400
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Laurenz Albe <laurenz.albe@cybertec.at> writes:
> On Thu, 2023-10-05 at 21:44 +0000, PG Bug reporting form wrote:
>> The english dictionary is using the lexeme "proxi" for the token "proxy=
". As
>> a result, the search term "proxy" is not yielding results for records t=
hat
>> contain this word.

> I cannot reproduce that.

Me either.  It suggests that you're trying to match against documents
that haven't been put through the same normalization process as the
query.

>> I think this lexeme was chosen to support the plural of proxy which is
>> proxies. However there are other plurals where the root word is spelled
>> different and Postgres creates the correct lexeme such as: [goose or mo=
use]

> The snowball dictionary has no real knowledge of the words.  Stemming is
> done by applying some heuristics which work "well enough" in most cases.

Yeah.  I don't see anything hugely wrong with this particular
transformation.  It is doing something useful, in that "proxy"
and "proxies" are both converted to the same lexeme "proxi".
In an ideal world, the lexeme would be "proxy", but it doesn't
really make that much difference if it isn't.

In any case, changing it now wouldn't be very practical, because
existing documents will already have been made into tsvectors
using this rule.

			regards, tom lane