Re: libpq: why only one PQsendQuery per connection at a time? - Mailing list pgsql-general

From David G Johnston
Subject Re: libpq: why only one PQsendQuery per connection at a time?
Date
Msg-id 1420393538131-5832807.post@n5.nabble.com
Whole thread Raw
In response to libpq: why only one PQsendQuery per connection at a time?  (sftf-misc@mail.ru)
List pgsql-general
sftf-2 wrote
> So question is why this limitaion exists?
>
> Why PQgetResult(PGconn *conn) operates on connection,
> and not on some unique handler that each "PQsend*" could return.
>
> Is it limitaion of libpq or architecture of postgresql backend or
> backend-frontend protocol?

IIUC this is a backend Postgres limitation - it was designed in a least
complex way where each process acts in a serial fashion.  A single process
has no way to maintain concurrent state for multiple active queries.

David J.



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