Re: assembling PGresults from multiple simultaneous queries (libpq, singlerowmode)

Never mind, I found the link to the github in emails from the link. Thanks
again!

Konstantin

On Sun, Apr 7, 2019 at 1:28 PM Konstantin Izmailov <pgfizm(at)gmail(dot)com> wrote:

> Yes, Andres, I meant "pipelining", just couldn't choose correct word.
> Thank you for the answer(s)!
>
> I also made changes in my own copy of libpq, and they work fine. I think
> the pipelining support is needed in libpq. Btw, how can I get the patch
> code? I want to compare your approach with mine. I couldn't figure out how
> to get the patch from the link.
>
> Thanks so much!
>
>
> On Sun, Apr 7, 2019 at 12:21 PM Andres Freund <andres(at)anarazel(dot)de> wrote:
>
>> Hi,
>>
>> On 2019-04-07 20:57:56 +0200, Pavel Stehule wrote:
>> > ne 7. 4. 2019 v 20:47 odesílatel Konstantin Izmailov <pgfizm(at)gmail(dot)com>
>> > napsal:
>> >
>> > > Hi,
>> > > I'm experimenting with Postgres 10 and protocol v3. I noticed that the
>> > > Postgres allows executing multiple queries simultaneously (I basically
>> > > commented out a check that prevents sending another query in libpq
>> while
>> > > previous result(s) reading is not complete). Things appear like
>> working,
>> > > but I just wanted to ask if anyone else tried the same (logically
>> separate
>> > > results from multiple simultaneous queries)?
>> > >
>> > >
>> > Postgres cannot to execute simultaneous queries in one session. So
>> queries
>> > should be executed in serial form every time.
>>
>> I think what Konstantin is really talking about is pipelining
>> (i.e. sending multiple queries without waiting for the results
>> inbetween, thereby reducing latency), and that is actually supported by
>> postgres. Some drivers make fairly extensive use of it (e.g. the pgjdbc
>> driver).
>>
>> As for libpq: No, that's currently not supported. There is a patch that
>> I hope to get into v13 however: https://commitfest.postgresql.org/20/1317
>>
>> Greetings,
>>
>> Andres Freund
>>
>