Re: Parallel threads in query

>
> In theory, simulating such global limit should be possible using a bit
> of shared memory for the current total, per-process counter and probably
> some simple abort handling (say, just like contrib/openssl does using
> ResourceOwner).
>

I would expect that this limit is already available and it's parallel
worker limit. Basically, when start a new thread I would like to somehow
consume a part of parallel worker limit - a thread is a kind of parallel
worker, from user's perspective. If I have 4 cores and Postgres already
started 4 parallel workers, I don't really want to start 4 threads for each
of them, or 4 for one of them and 1 for each of the rest, if I manage that
separately from parallel worker limit.

IPC and co - that's another question and out of scope for this one. Since
OpenMP allows to write multithreaded code by just adding more #pragma
around loops, I don't want to reinvent that part of infrastructure.
--
Darafei Praliaskouski
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