Horton
Menu

Re: Add Pipelining support in psql

Jelte Fennema <postgres@jeltef.nl>

View thread
From: Jelte Fennema-Nio <postgres@jeltef.nl>
To: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2024-11-27T12:45:32Z
Lists: pgsql-hackers 
On Wed, 27 Nov 2024 at 10:50, Anthonin Bonnefoy
<anthonin.bonnefoy@datadoghq.com> wrote:
> With \bind, \parse, \bind_named and \close, it is possible to issue
> queries from psql using the extended protocol. However, it wasn't
> possible to send those queries using pipelining and the only way to
> test pipelined queries was through pgbench's tap tests.

Big +1. Not being able to use psql for even the most basic pipeline
tests has definitely been an annoyance of mine.

I played around quickly with this patch and it works quite well. A few
things that would be nice improvements I think. Feel free to change
the command names:
1. Add a \flush command that calls PQflush
2. Add a \flushrequest command that calls PQsendFlushRequest
3. Add a \getresult command so you can get a result from a query
without having to close the pipeline

To be clear, not having those additional commands isn't a blocker for
this patch imho, but I'd definitely miss them if they weren't there
when I would be using it.

Commits

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

  1. psql: Fix assertion failures with pipeline mode

  2. psql: Rework TAP routine psql_fails_like() to define WAL sender context

  3. psql: Split extended query protocol meta-commands in --help=commands

  4. psql: Improve descriptions of \\flush[request] in --help

  5. psql: Fix incorrect status code returned by \getresults

  6. psql: Allow queries terminated by semicolons while in pipeline mode

  7. psql: Add \sendpipeline to send query buffers while in a pipeline

  8. psql: Fix memory leak with \gx used within a pipeline

  9. psql: Add pipeline status to prompt and some state variables

  10. Add more tests for utility commands in pipelines

  11. psql: Add support for pipelines

  12. Add braces for if block with large comment in psql's common.c