Re: [PATCH v2] Progress command to monitor progression of long running SQL queries

On Tue, May 16, 2017 at 7:26 PM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:

> On Tue, May 16, 2017 at 2:17 AM, Michael Paquier
> <michael(dot)paquier(at)gmail(dot)com> wrote:
> > Perhaps DSM? It is not user-friendly to fail sporadically...
>
> Yeah. I've been thinking we might want to give each backend a
> backend-lifetime DSA that is created on first use. That could be
> useful for some parallel query stuff and maybe for this as well.
> Other backends could attach to it to read data from it, and it would
> go away on last detach (which would normally be the detach by the
> creating backend, but not if somebody else happens to be reading at
> the moment the backend exits).
>

That seems like a pretty good idea. I've been considering something simliar
for the usecase of being able to view the "collected but not sent yet"
statistics inside a backend (which tables have been accessed, number of
reads etc),and this seems like it could be used for that as well.

--
Magnus Hagander
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