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BUG #17125: Operator precedence bug in websearch_to_tsquery function
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* BUG #17125: Operator precedence bug in websearch_to_tsquery function
@ 2021-07-28 01:39  PG Bug reporting form <noreply@postgresql.org>
  0 siblings, 1 reply; 3+ messages in thread

From: PG Bug reporting form @ 2021-07-28 01:39 UTC (permalink / raw)
  To: pgsql-bugs@lists.postgresql.org; +Cc: tim.connolly@oovvuu.com

The following bug has been logged on the website:

Bug reference:      17125
Logged by:          Tim Connolly
Email address:      tim.connolly@oovvuu.com
PostgreSQL version: 11.12
Operating system:   Alpine Linux
Description:        

Expectation: A web-search query of 'foo bar or baz' should match documents
that contain 'foo' and 'bar', and documents that contain 'foo' and 'baz'.


postgres=# select to_tsvector('english', 'baz') @@
websearch_to_tsquery('english', 'foo bar or baz ');
 ?column?
----------
 t
(1 row)

Expected: f

postgres=# select websearch_to_tsquery('english', 'foo bar or baz');
 websearch_to_tsquery
-----------------------
 'foo' & 'bar' | 'baz'
(1 row)

Expected: 'foo' & ('bar' | 'baz')



^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: BUG #17125: Operator precedence bug in websearch_to_tsquery function
@ 2021-07-28 13:40  David G. Johnston <david.g.johnston@gmail.com>
  parent: PG Bug reporting form <noreply@postgresql.org>
  0 siblings, 1 reply; 3+ messages in thread

From: David G. Johnston @ 2021-07-28 13:40 UTC (permalink / raw)
  To: tim.connolly@oovvuu.com <tim.connolly@oovvuu.com>; pgsql-bugs@lists.postgresql.org <pgsql-bugs@lists.postgresql.org>

On Tuesday, July 27, 2021, PG Bug reporting form <noreply@postgresql.org>
wrote:

>
> postgres=# select websearch_to_tsquery('english', 'foo bar or baz');
>  websearch_to_tsquery
> -----------------------
>  'foo' & 'bar' | 'baz'
> (1 row)
>
> Expected: 'foo' & ('bar' | 'baz')
>
>
The documentation describes the operator precedence and it isn’t what you
expect.


https://www.postgresql.org/docs/current/datatype-textsearch.html#DATATYPE-TSQUERY


David J.

^ permalink  raw  reply  [nested|flat] 3+ messages in thread

* Re: BUG #17125: Operator precedence bug in websearch_to_tsquery function
@ 2021-07-28 14:13  Tom Lane <tgl@sss.pgh.pa.us>
  parent: David G. Johnston <david.g.johnston@gmail.com>
  0 siblings, 0 replies; 3+ messages in thread

From: Tom Lane @ 2021-07-28 14:13 UTC (permalink / raw)
  To: David G. Johnston <david.g.johnston@gmail.com>; +Cc: tim.connolly@oovvuu.com <tim.connolly@oovvuu.com>; pgsql-bugs@lists.postgresql.org <pgsql-bugs@lists.postgresql.org>

"David G. Johnston" <david.g.johnston@gmail.com> writes:
> On Tuesday, July 27, 2021, PG Bug reporting form <noreply@postgresql.org>
> wrote:
>> postgres=# select websearch_to_tsquery('english', 'foo bar or baz');
>> websearch_to_tsquery
>> -----------------------
>> 'foo' & 'bar' | 'baz'
>> (1 row)
>> 
>> Expected: 'foo' & ('bar' | 'baz')

> The documentation describes the operator precedence and it isn’t what you
> expect.

It does appear from what I could find on the web that Google does it
the other way.  Whether that's enough reason to change a behavior
that's stood since v11 is hard to say.  We're not trying to be
entirely bug-compatible with Google here ... and even if we were,
who's to say whether they might not change this tomorrow?

Perhaps a more useful way to think about it is whether it's possible
to get the behavior opposite to the default.  AFAICS there isn't any
way to get 'a & (b | c)' out of websearch_to_tsquery.  However, if
we changed the default precedence, then there'd be no way to get the
old behavior, which is not nice at all.  I first thought that maybe
you could write '"a b" or c', but that produces 'a <-> b | c' which
isn't the same.

Anyway, given that most people probably have no idea about this fine
point, I doubt that the benefits of changing it would outweigh the
costs.

			regards, tom lane





^ permalink  raw  reply  [nested|flat] 3+ messages in thread


end of thread, other threads:[~2021-07-28 14:13 UTC | newest]

Thread overview: 3+ messages (download: mbox mbox.gz follow: Atom feed)
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2021-07-28 01:39 BUG #17125: Operator precedence bug in websearch_to_tsquery function PG Bug reporting form <noreply@postgresql.org>
2021-07-28 13:40 ` David G. Johnston <david.g.johnston@gmail.com>
2021-07-28 14:13   ` Tom Lane <tgl@sss.pgh.pa.us>

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