Re: [PATCH] 2PC state files on shared memory

Michael Paquier <michael.paquier@gmail.com> writes:
> Based on an idea of Heikki Linnakangas, here is a patch in order to improve
> 2PC
> by sending the state files of prepared transactions to shared memory instead
> of disk.

I don't understand how this can possibly work.  The entire point of
2PC is that the state file is guaranteed to be on disk so it will
survive a crash.  What good is it if it's in shared memory?

Quite aside from that, the fixed size of shared memory makes this seem
pretty impractical.
        regards, tom lane