Re: SQL Property Graph Queries (SQL/PGQ)

In the ddl.sgml, I’d swap the first two paragraphs.
I find the first one a bit confusing as-is. As far as I can tell, it’s an implementation detail.
The first paragraph should answer, “I have some data modeled as a graph G=(V, E). Can Postgres help me?”.

Then, introducing property graphs makes more sense.

I'd also use the examples and fake data in `graph_table.sql` in ddl/queries.sgml).
I was bummed that that copy-pasting didn't work as is.
I’d keep explaining how a graph query translates to a relational one later in the page.

As for the implementation, I can’t have an opinion yet,
but for those not familiar, Apache Age uses a slightly different approach
that mimics jsonpath (parses a sublanguage expression into an internal execution engine etc.).
However, the standard requires mapping this to the relational model, which makes sense for core Postgres.


> On 27 Jun 2024, at 3:31 PM, Peter Eisentraut <peter@eisentraut.org> wrote:
>
> Here is a new version of this patch.  I have been working together with Ashutosh on this.  While the version 0 was
moreof a fragile demo, this version 1 has a fairly complete minimal feature set and should be useful for playing around
with. We do have a long list of various internal bits that still need to be fixed or revised or looked at again, so
thereis by no means a claim that everything is completed. 
>
> Documentation to get started is included (ddl.sgml and queries.sgml). (Of course, feedback on the getting-started
documentationwould be most welcome.) 
> <v1-0001-WIP-SQL-Property-Graph-Queries-SQL-PGQ.patch>