Re: Add Pipelining support in psql - Mailing list pgsql-hackers

From Daniel Verite
Subject Re: Add Pipelining support in psql
Date
Msg-id ad4b9f1a-f7fe-4ab8-8546-90754726d0be@manitou-mail.org
Whole thread Raw
List pgsql-hackers
    Anthonin Bonnefoy wrote:

> > What is the reasoning here behind this restriction?  \gx is a wrapper
> > of \g with expanded mode on, but it is also possible to call \g with
> > expanded=on, bypassing this restriction.
>
> The issue is that \gx enables expanded mode for the duration of the
> query and immediately reset it in sendquery_cleanup. With pipelining,
> the command is piped and displaying is done by either \endpipeline or
> \getresults, so the flag change has no impact. Forbidding it was a way
> to make it clearer that it won't have the expected effect

But it's not just \gx

The following invocations don't respect the desired output destination
and formats (ignoring them), when a pipeline is active:

select ... \bind \g filename
select ... \bind \g |program
select ... \bind \g (format=unaligned tuples_only=on)

Just like for \gx the problem is that in a pipeline, sending the query
is not followed by getting the results, and the output properties
of a query are lost in between.


Best regards,
--
Daniel Vérité
https://postgresql.verite.pro/



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