Re: libpq pipelineing

Thanks David,

You are correct.

I was giving an example of what I was hoping to achieve, not what I
expected to work with the current interface.

I found some discussion in the past relating to batch processing which
appears to support some kind of pipelining:

https://2ndquadrant.github.io/postgres/libpq-batch-mode.html

However it seems to be abandoned.

Kind regards,
Samuel

On Sat, 27 Jun 2020 at 16:15, David G. Johnston
<david(dot)g(dot)johnston(at)gmail(dot)com> wrote:
>
> On Friday, June 26, 2020, Samuel Williams <space(dot)ship(dot)traveller(at)gmail(dot)com> wrote:
>>
>> Hello,
>>
>> Using the asynchronous interface of libpq, is it possible to pipeline
>> multiple queries?
>>
>> i.e.
>>
>> PQsendQuery(query1)
>> PQsendQuery(query2)
>>
>> followed by
>>
>> query1_results = PQgetResult(...)
>> query2_results = PQgetResult(...)
>>
>> I tried it but got "another command is already in progress" error.
>
>
> The documentation seems to leave zero ambiguity:
>
> After successfully calling PQsendQuery, call PQgetResult one or more times to obtain the results. PQsendQuery cannot be called again (on the same connection) until PQgetResult has returned a null pointer, indicating that the command is done.
>
> David J.
>