Re: Non-blocking queries in postgresql - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: Non-blocking queries in postgresql
Date
Msg-id 199901261543.KAA12203@candle.pha.pa.us
Whole thread Raw
List pgsql-hackers
> 
> Bruce Momjian wrote:
> 
> > > Thank you very much for the response of the other mail i`ve sent.
> > >     I want to make you a very important question. This is critical
> > for
> > > my pourposes and i cannot find a clear answer in the documentation
> > of
> > > postgres.
> > >     There is a capability in Oracle that allows you to make
> > > "non-blocking queries". That`s it. The normal query from a program,
> > > throw an API to the DBMS, opens a socket, and waits untill the
> > response
> > > comes. But the other way, returns the control inmediatly and the
> > user
> > > must poll on this socket to know when the answer comes.
> > >     My english is poor, but i hope you`ve understood what i`m
> > talking
> > > about. If it is not allowed in postgres i cannot use it as my
> > database.
> > > I have to make queries to other machines, and i cannot wait untill
> > the
> > > connection is made, and the response comes.
> > >     There is PQexec and i want to know how i could make a PQexecNB
> > > (non-blocking). In Oracle this is the diference of the two funcion
> > calls
> > > to the API.
> >
> > New feature in 6.4.*.  See the libpq manual under async.  You can send
> > a
> > query and poll to see when the result is ready.  See PQsendQuery() C
> > function call.  Also mention in the manuals in the docs directory.
> > You
> > can also use C function select() to wait for data from any number of
> > concurrent backend sockets.
> >
> > --
> >   Bruce Momjian                        |  http://www.op.net/~candle
> >   maillist@candle.pha.pa.us            |  (610) 853-3000
> >   +  If your life is a hard drive,     |  830 Blythe Avenue
> >   +  Christ can be your backup.        |  Drexel Hill, Pennsylvania
> > 19026
> 
> Thank you very much!!!
>     But I have a llitle problem. I`m afraid that the lipq++ interface
> doesn't have this funcion call. Is it true?
> Have you got any examples of the using of PQsendQuery and Non Blocking
> queries using this interface lipq or libpq++? I will be very usefull for
> me. Just simply attach it on the response.
> 
> It would be very appreciated. Thank you again.

Maybe it hasn't been added to libpq++ yet.

--  Bruce Momjian                        |  http://www.op.net/~candle maillist@candle.pha.pa.us            |  (610)
853-3000+  If your life is a hard drive,     |  830 Blythe Avenue +  Christ can be your backup.        |  Drexel Hill,
Pennsylvania19026
 


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