Re: PG 14 release notes, first draft

.On Tue, May 11, 2021 at 11:31 PM Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> On Tue, May 11, 2021 at 01:16:38PM +0300, Alexander Korotkov wrote:
> > > OK, what symbols trigger this change? Underscore? What else?
> >
> > Any symbol, which is recognized as a separator by full-text parser,
> > but not tsquery parser. Fulltext search is extensible and allowing
> > pluggable parsers. In principle, we could dig the exact set of
> > symbols, but I'm not sure this worth the effort.
> >
> > > You are
> > > saying the previous code allowed 'pg' and 'class' anywhere in the
> > > string, while the new code requires them to be adjacent, which more
> > > closely matches the pattern.
> >
> > Yes, that's it.
> >
> > > > * Fix extra distance in phrase operators for quoted text in
> > > > websearch_to_tsquery() (Alexander Korotkov)
> > > > For example, websearch_to_tsquery('english', '"aaa: bbb"') becomes
> > > > 'aaa <> bbb' instead of 'aaa <2> bbb'.
> > >
> > > So colon and space were considered to be two tokens between 'aaa' and
> > > 'bbb', while is really only one because both tokens are discarded? Is
> > > this true of any discarded tokens, e.g. ''"aaa ?:, bbb"'?
> >
> > Yes, that's true for any discarded tokens.
>
> I can up with this text for these two items. I think it still needs ro
> be more specific:
>
> <listitem>
> <!--
> Author: Alexander Korotkov <akorotkov(at)postgresql(dot)org>
> 2021-01-31 [0c4f355c6] Fix parsing of complex morphs to tsquery
> -->
>
> <para>
> Fix to_tsquery() and websearch_to_tsquery() to properly parse
> certain discarded tokens in quotes (Alexander Korotkov)
> </para>

This relates not just to quotes. Original problem relates to quotes
in websearch_to_tsquery() and phrase operator in to_tsquery(). But
the solution changes output for all query operands containing
discarded tokens.

Could we try this?

Make to_tsquery() and websearch_to_tsquery() produce more strict
output for query parts containing discarded tokens. In particular,
this makes to_tsquery() and websearch_to_tsquery() properly parse the
discarded tokens in phrase search operands and quotes correspondingly.

> <para>
> Certain discarded tokens, like underscore, caused the output
> of these functions to produce incorrect tsquery output, e.g.,
> websearch_to_tsquery('"pg_class pg"') used to output '( pg &
> class ) <-> pg', but now outputs 'pg <-> class <-> pg'.
> </para>
> </listitem>

This part looks good to me. I'd just suggest to extend the example to
to_tsquery() as well.

Certain discarded tokens, like underscore, caused the output of these
functions to produce incorrect tsquery output, e.g., both
websearch_to_tsquery('"pg_class pg"') and to_tsquery('pg_class <->
pg') used to output '( pg & class ) <-> pg', but now both output 'pg
<-> class <-> pg'.

> <listitem>
> <!--
> Author: Alexander Korotkov <akorotkov(at)postgresql(dot)org>
> 2021-05-03 [eb086056f] Make websearch_to_tsquery() parse text in quotes as a si
> -->
>
> <para>
> Fix websearch_to_tsquery() to properly parse multiple adjacent
> discarded tokens in quotes (Alexander Korotkov)
> </para>
>
> <para>
> Previously, quoted text that contained multiple adjacent discarded
> tokens were treated as multiple tokens, causing incorrect tsquery
> output, e.g., websearch_to_tsquery('"aaa: bbb"') used to output
> 'aaa <2> bbb', but now outputs 'aaa <-> bbb'.
> </para>
> </listitem>

This item looks good to me.

------
Regards,
Alexander Korotkov