On Sat, Aug 29, 2015 at 12:55 PM, Thomas Munro <thomas.mu...@enterprisedb.com> wrote: > On Sat, Aug 29, 2015 at 9:03 AM, Thomas Munro > <thomas.mu...@enterprisedb.com> wrote: >> >> On Fri, Aug 28, 2015 at 10:30 PM, jacques klein >> <jacques.k...@googlemail.com> wrote: >>> >>> Hello, >>> >>> I added a "NOFITY chan" to the SQL arg of an SPI_execute(), (I did it >>> also with just the NOTIFY statement), >>> but the listeners (other workers) don't get the notification until a >>> "NOTIFY chan" is done for example with pgadmin, >>> >>> They don't get lost, just not emited after the "not forgotten" call of >>> CommitTransactionCommand(). >>> >>> Is this normal ( i.e. not supported (yet) ), a bug, or did I overlook >>> some doc. (or source code) ?. >>> >>> For now, I will try to "emit" the NOTIFY via libpq. >> >> >> That's because ProcessCompletedNotifies isn't being called. For regular >> backends it is called inside the top level loop PostgresMain. I think you >> need to include "commands/async.h" and add a call to >> ProcessCompletedNotifies() after your background worker commits to make this >> work. > > > For the record, Jacques confirmed off-list that this worked, and I also did > a couple of tests. > > Is this expected? If so, should it be documented -- perhaps with something > like the attached? Alternatively there may be some way to make > CommitTransactionCommand do it, though the comments in > ProcessCompletedNotifies explain why that was rejected, at least as far as > AtCommit_Notify goes. > > This made me wonder what happens if a background worker calls LISTEN. > NotifyMyFrontEnd simply logs the notifications, since there is no remote > libpq to sent a message to. Perhaps a way of delivering to background > workers could be developed, though of course there are plenty of other kinds > of IPC available already.
Yes, the Notify command execution is possible with call to ProcessCompletedNotifies function in a background worker and the Listen command is not possible in background worker because of no client associated with it. The documentation patch provides a better understanding to the user regarding notify and listen commands. I marked this patch as ready for committer. Regards, Hari Babu Fujitsu Australia -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers