Re: Support Parallel Query Execution in Executor

Greg Stark wrote:
> Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
>
> > An idea arising in chat with Joshua Drake: the retargetting code, if it
> > turns out to work and not be excessively expensive, could also be useful
> > to implement a server-side "connection pooling" of sorts: the postmaster
> > could keep idle backends and retarget them to a database that receives
> > an incoming connection. However, we'd also need a mechanism to clean
> > all backend state previous to reusing a connection, to leave it "as
> > new" (no prepared statements, WITH HOLD cursors, etc.)
>
> Isn't all that work pretty much exactly the main cost of starting a new
> backend?

On Linux and other systems were fork() has negligible cost, maybe; but
on Windows and Solaris, it's certainly not.

--
Alvaro Herrera http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.