Re: Add new protocol message to change GUCs for usage with future protocol-only GUCs

Robert Haas <robertmhaas@gmail.com>

From: Robert Haas <robertmhaas@gmail.com>

To: Jelte Fennema-Nio <me@jeltef.nl>

Cc: Tom Lane <tgl@sss.pgh.pa.us>, Jacob Burroughs <jburroughs@instructure.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Dave Cramer <davecramer@gmail.com>, "Andrey M. Borodin" <x4mmm@yandex-team.ru>, Pavel Stehule <pavel.stehule@gmail.com>, Jeff Davis <pgsql@j-davis.com>, Peter Eisentraut <peter@eisentraut.org>

Date: 2024-01-05T17:26:18Z

Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

libpq: Add min/max_protocol_version connection options
- 285613c60a7a 18.0 landed
libpq: Handle NegotiateProtocolVersion message differently
- 5070349102af 18.0 landed
Add PQfullProtocolVersion() to surface the precise protocol version.
- cdb6b0fdb0b2 18.0 landed
Do not hardcode PG_PROTOCOL_LATEST in NegotiateProtocolVersion
- 516b87502dc1 18.0 landed
libpq: Handle NegotiateProtocolVersion message
- bbf9c282ce92 16.0 cited
Provide for forward compatibility with future minor protocol versions.
- ae65f6066dc3 11.0 cited

On Fri, Jan 5, 2024 at 12:20 PM Jelte Fennema-Nio <me@jeltef.nl> wrote:
> They are not fundamentally transactional afaict based on the changes
> that were needed so far. It makes sense too, because e.g. SIGHUP
> should change the GUC value if the config changed no matter if the
> current transaction aborts or succeeds.

Well, AtEOXact_GUC either reverts or puts back changes to GUC values
that have happened in that (sub)transaction, depending on whether the
(sub)transaction committed or aborted. To make that work, there's a
"stack" of GUC values for any given setting. For a non-transactional
value, we wouldn't have all that infrastructure...

-- 
Robert Haas
EDB: http://www.enterprisedb.com