> Thanks for your explanation, I checked it again and it looks a very clean > method. The attached is a draft patch based on my understanding. Hope > I didn't misunderstand you..
Ah, I was going to play arond with that today, but you beat me to it ;-)
Very glad to be helpful.
A few thoughts after a quick look at the patch:
* I had envisioned that there's a custom GUC controlling the lock ID used; this would allow blocking different sessions at different points, if we ever need that. Also, I'd make the GUC start out as zero which means "do nothing", so that merely loading the module has no immediate effect.
I forgot to say I didn't get the point of the guc variable in the last thread,
now I think it is a smart idea, so added it. In this way, one session
can only be blocked at one place, it may not be an issue in practise.
* Don't really see the point of the before-planning lock.
yes.. it was removed now.
* Rather than exposing internal declarations from lockfuncs.c, you could just write calls to pg_advisory_lock_int8 etc. using DirectFunctionCall1.
Thanks for sharing it, this method looks pretty good.
* We need some better name than "test_module". I had vaguely thought about "delay_execution", but am surely open to better ideas.
Both names look good to me, delay_execution looks better, it is used in v2.
