Re: Support Parallel Query Execution in Executor

Greg Stark wrote:
> Alvaro Herrera <alvherre@commandprompt.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.