In PG11, I propose the following command, sticking mostly to Ants'
syntax, and allowing to wait for multiple events before it returns. It
doesn't hold snapshot and will not get cancelled by Hot Standby.
WAIT FOR event [, event ...] options
event is
LSN value
TIMESTAMP value
options
TIMEOUT delay
UNTIL TIMESTAMP timestamp
(we have both, so people don't need to do math, they can use whichever
they have)
I have a (possibly) dumb question: if we have specified several events,
should WAIT finish if only one of them triggered? It's not immediately
obvious if we're waiting for ALL of them to trigger, or just one will
suffice (ANY). IMO the syntax could be extended to something like:
WAIT FOR [ANY | ALL] event [, event ...] options,
with ANY being the default variant.
--
Dmitry Ivanov
Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company
