From dde5f09fad3ac188a155e21667f76825f43a28c8 Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Fri, 6 Nov 2015 00:31:03 -0500 Subject: [PATCH] Document interaction of bgworkers with LISTEN/NOTIFY. Thomas Munro and Robert Haas, reviewed by Haribabu Kommi --- doc/src/sgml/bgworker.sgml | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/doc/src/sgml/bgworker.sgml b/doc/src/sgml/bgworker.sgml index 505e362879..5570ed045d 100644 --- a/doc/src/sgml/bgworker.sgml +++ b/doc/src/sgml/bgworker.sgml @@ -277,6 +277,18 @@ typedef struct BackgroundWorker BGWH_POSTMASTER_DIED. + + If a background worker sends asynchronous notifications with the + NOTIFY command via the Server Programming Interface + (SPI), it should call + ProcessCompletedNotifies explicitly after committing + the enclosing transaction so that any notifications can be delivered. If a + background worker registers to receive asynchronous notifications with + the LISTEN through SPI, the worker + will log those notifications, but there is no programmatic way for the + worker to intercept and respond to those notifications. + + The worker_spi contrib module contains a working example, which demonstrates some useful techniques. -- 2.40.0