Re: Add Pipelining support in psql

Michael Paquier <michael@paquier.xyz>

From: Michael Paquier <michael@paquier.xyz>
To: Jelte Fennema-Nio <postgres@jeltef.nl>
Cc: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>, Daniel Verite <daniel@manitou-mail.org>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2025-03-19T02:28:54Z
Lists: pgsql-hackers
On Tue, Mar 18, 2025 at 10:27:38AM +0100, Jelte Fennema-Nio wrote:
> One thing that comes to mind that I think would be quite useful and
> pretty easy to implement if we have this functionality within a
> pipeline: An \extended command. That puts psql in "extended protocol
> mode" (without enabling pipelining). In "extended protocol mode" all
> queries would automatically be sent using PQsendQueryParams. That
> would remove the need to use \bind anymore outside of a pipeline
> either.

How does that help when passing parameter values?  \bind is here to be
able to pass down parameter values to queries that are prepared, so we
cannot bypass it as the parameter values need to be passed to the
\bind meta-command itself.

Perhaps an \extended command that behaves outside a pipeline makes
sense to force the use of queries without parameters to use the
extended mode, but I cannot get much excited about the concept knowing
all the meta-commands we have now (not talking about the pipeline
part, which is different, as we can treat queries in batches).
--
Michael

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