Hello Andy and others, On Mon, Nov 1, 2010 at 3:33 PM, Andy Colson <andy@xxxxxxxxxxxxxxx> wrote: > On 11/1/2010 4:29 AM, Alexander Farber wrote: >> I have a small multiplayer game, a non-forking daemon >> reading/writing to sockets and running in a IO::Poll loop. >> >> I.e. I would like to "fire and forget" queries. >> >> But unfortunately I get the error: >> DBD::Pg::st execute failed: Cannot execute >> until previous async query has finished >> even though I'm not using PG_OLDQUERY_WAIT > I believe one database connection can have one async query going at a time. why are there 3 contants http://search.cpan.org/dist/DBD-Pg/Pg.pm#Asynchronous_Constants then? They suggest you can fire a query and forget > I dont see anyplace in the docs that connect (or connect_cached) supports > PG_ASYNC. True, I've removed it (the problem still persists). > Each iteration of your loop is blowing away the previous values, which > should cause problems. I assume this is just test code? Is your real code > really going to connection 10 times per person? You wont be able to support > very many concurrent users that way. The code above might work if you > switched it arrays (@dbh and @sth). No I just need one connection, because I have 1 process (without any forked processes or threads), which loops in a poll() loop. > Async queries gives you the ability to fire one query, let the db work on it > while you do something else, and them come back to it. You need to think > about your layout (cuz I'm betting your example code does not reflect what > you really want to do). > > Even with async querys, you eventually have to call $dbh->pg_result, so its > not going to be fire and forget. To really do fire and forget, and totally > take the stats processing away from game play processing, I'd suggest an > event queue (or rpc), like zeromq, PGQ or gearman. Thanks I'll look at it or maybe I'll fork 1 more process, and open a pipe to it (then I can poll() it too). Regards Alex -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
