Horton

Re: Make query cancellation keys longer

Robert Haas <robertmhaas@gmail.com>

View thread View on postgr.es
From: Robert Haas <robertmhaas@gmail.com>
To: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: Jelte Fennema-Nio <postgres@jeltef.nl>, pgsql-hackers <pgsql-hackers@postgresql.org>, Thomas Munro <thomas.munro@gmail.com>
Date: 2024-08-16T15:29:17Z
Lists: pgsql-hackers 
On Fri, Aug 16, 2024 at 10:37 AM Heikki Linnakangas <hlinnaka@iki.fi> wrote:
> If we envision accepting ranges like that in the future, it would be
> good to do now rather than later. Otherwise, if someone wants to require
> features from protocol 3.2 today, they will have to put
> "protocol_version=3.2" in the connection string, and later when 3.3
> version is released, their connection string will continue to force the
> then-old 3.2 version.

I'm totally cool with doing it now rather than later if you or someone
else is willing to do the work. But I don't see why we'd need a
protocol bump to change it later. If you write protocol_version=3.7 or
protocol_version=3.2-3.7 we send the same thing to the server either
way. It's only a difference in whether we slam the connection shut if
the server comes back and say it can only do 3.0.

> I'll split this patch like that, to make it easier to compare and merge
> with Jelte's corresponding patches.

That sounds great. IMHO, comparing and merging the patches is the next
step here and would be great to see.

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

Commits

  1. Add timingsafe_bcmp(), for constant-time memory comparison

  2. Add missing declarations to pg_config.h.in

  3. docs: Add a new section and a table listing protocol versions

  4. Make cancel request keys longer

  5. libpq: Add min/max_protocol_version connection options

  6. libpq: Handle NegotiateProtocolVersion message differently

  7. docs: Update phrase on message lengths in the protocol

  8. libpq: Trace all NegotiateProtocolVersion fields

  9. libpq: Add PQfullProtocolVersion to exports.txt

  10. Move cancel key generation to after forking the backend