On Mon, Oct 31, 2011 at 12:49 PM, Mark Hills <mark.hi...@framestore.com> wrote: > On Mon, 31 Oct 2011, Tom Lane wrote: > >> Heikki Linnakangas <heikki.linnakan...@enterprisedb.com> writes: >> > On 31.10.2011 17:44, Mark Hills wrote: >> >> Could libpq be reasonably modified to allow this? >> >> > I believe it's doable in theory, no-one has just gotten around to it. >> > Patches are welcome. >> >> Can't you do that today with a multi-command string submitted to >> PQsendQuery, followed by multiple calls to PQgetResult? > > I remember something about this; I think I concluded that it validated > that receiving multiple results could be done this way. > > But this kind of batching can't be used with prepared queries. > >> I'm hesitant to think about supporting the case more thoroughly than >> that, or with any different semantics than that, because I think that >> the error-case behavior will be entirely unintelligible/unmaintainable >> unless you abandon all queries-in-flight in toto when an error happens. > > Can you explain a bit more detail which errors are of most concern, do you > mean full buffers on the client send? > > Because the content of the stream going to/from the server does not > change, I wouldn't really expect the semantics to change. For example, the > server cannot even see that the client is behaving in this way. Are there > any 'send' functions that are heavily reliant on some kind of > result/receive state? > > I don't disagree with the comments above though, any shift towards > unintelligible behaviour would be very bad. > >> Furthermore, in most apps it'd be a serious PITA to keep track of which >> reply is for which query, so I doubt that such a feature is of general >> usefulness. > > In our UI case, we already have a queue. Because libpq can't pipeline > multiple queries, we have to make our own queue of them anyway.
Note, nothing is keeping you from opening up a second connection and interleaving in that fashion, so 'libpq' is not the bottleneck, the connection object is :-). merlin -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers