On Sat, May 4, 2019 at 3:04 PM Igal Sapir <i...@lucee.org> wrote: > Jeff, > > On Sat, May 4, 2019 at 11:34 AM Jeff Janes <jeff.ja...@gmail.com> wrote: > >> On Sat, May 4, 2019 at 1:49 PM Igal Sapir <i...@lucee.org> wrote: >> >>> Christoph, >>> >>> On Sat, May 4, 2019 at 10:44 AM Christoph Moench-Tegeder < >>> c...@burggraben.net> wrote: >>> >>>> ## Igal Sapir (i...@lucee.org): >>>> >>>> > My main "issue" is that the official pgjdbc driver does not support >>>> the >>>> > notifications with listen and I was trying to figure out why. >>>> >>>> https://jdbc.postgresql.org/documentation/head/listennotify.html >>>> >>>> >>> I should have been more explicit. My main issue is with the following >>> statement from the link that you posted: >>> >>> > A key limitation of the JDBC driver is that it cannot receive >>> asynchronous notifications and must poll the backend to check if any >>> notifications were issued >>> >>> Polling is much less efficient than event handling and I'm sure that >>> there's a major performance hit with that. >>> >> >> Isn't that addressed here?: >> >> // If this thread is the only one that uses the >> connection, a timeout can be used to >> // receive notifications immediately: >> // org.postgresql.PGNotification notifications[] = >> pgconn.getNotifications(10000); >> >> > It "helps", but it's still not the same as keeping the connection open and > receiving messages in real time. >
But it is the same as that. It keeps the connection open, and receives the messages in real time. It blocks either until it gets a NOTIFY, or for 10 seconds, whichever occurs first. You can use 0 to block forever until a NOTIFY arrives. Maybe you didn't remove the sleep a few lines further down? Or is there some other problem here? Cheers, Jeff >
