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Date: Tue, 13 Jan 2026 11:12:08 +0100
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Subject: Re: SQL Property Graph Queries (SQL/PGQ)
To: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
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On 18.12.25 10:15, Ashutosh Bapat wrote:
> I was aware of ecpg and I vaguely remember we fixed something in ECPG
> to allow : in MATCH statement. Probably following changes in
> psqlscan.l and pgc.l
> -self                   [,()\[\].;\:\+\-\*\/\%\^\<\>\=]
> +self                   [,()\[\].;\:\|\+\-\*\/\%\^\<\>\=]
> 
> Those changes add | after : (and not the : itself) so maybe they are
> not about supporting : . Do you remember what those are?

These are required to support label disjunctions.  If you add one of 
those to the ecpg sqlpgq tests you added, like (c IS customer|customer), 
then it will fail to compile without this change.

The psql change has perhaps no such impact, but in general, these are 
supposed to be kept in sync with the main scan.l.

> In ddl.sgml I noticed a seemingly incomplete sentence
>     A property graph is a way to represent database contents, instead of using
>     relational structures such as tables.

Maybe it's clearer like this:

"A property graph is a way to represent database contents, as an 
alternative to the usual (in SQL) approach of representing database 
contents using relational structures such as tables."

> 0002 has extra tests mentioned above. It also removes "TODO: dubious
> error message" from a comment. I don't see anything dubious in the
> error message. I think this patch is safe to be merged into 0001.

Hmm, yeah, this might have been a leftover from a different catalog 
structure that resulted in different detail messages from the dependency 
infrastructure.  I can't see anything wrong with the current output either.