Re: Using ProcSignal to get memory context stats from a running backend

On 22.12.2017 16:56, Craig Ringer wrote:

On 22 December 2017 at 20:50, Maksim Milyutin <milyutinma@gmail.com> wrote:

On 19.12.2017 16:54, Pavel Stehule wrote:

sorry for small offtopic. Can be used this mechanism for log of executed plan or full query?

That's a really good idea. I'd love to be able to pg_explain_backend(...)

I left the mechanism as a generic diagnostic signal exactly so that we could add other things we wanted to be able to ask backends. I think a follow-on patch that adds support for dumping explain-format plans would be great, if it's practical to do that while a query's already running.

Noticing the interest in the calling some routines on the remote backend through signals, in parallel thread[1] I have proposed the possibility to define user defined signal handlers in extensions. There is a patch taken from pg_query_state module.

1. https://www.postgresql.org/message-id/3f905f10-cf7a-d4e0-64a1-7fd9b8351592%40gmail.com