markw@mohawksoft.com writes:
> The process vs threads benchmark which showed 160us vs 120us, only did
> the process creation, not the delayed hit of the "copy on write" pages
> in the new process. Just forking is not as simple as forking, once the
> forked process starts to work, memory that is not explicitly shared is
> copied to the new process once it is modified. So this is a hit,
> possibly a big hit.
There aren't going to be all that many data pages needing the COW
treatment, because the postmaster uses very little data space of its
own. I think this would become an issue if we tried to have the
postmaster pre-cache catalog information for backends, however (see
my post elsewhere in this thread).
regards, tom lane