Excerpts from Tom Lane's message of jue jun 02 15:49:53 -0400 2011: > Alexey Klyukin <al...@commandprompt.com> writes:
> > - Try to actually allocate the shared memory in a way postmaster does this > > nowadays, if the process fails - analyze the error code to check whether > > the > > failure is due to the shmmax or shmmall limits being too low. This would > > need to be run as a separate process (not postmaster's child) to avoid > > messing with the postmaster's own shared memory, which means that this > > would > > be hard to implement as a user-callable stored function. > > The results of such a test wouldn't be worth the electrons they're > written on anyway: you're ignoring the likelihood that two instances of > shared memory would overrun the kernel's SHMALL limit, when a single > instance would be fine. > > Given that you can't do it in the context of a live installation, just > trying to start the postmaster and seeing if it works (same as initdb > does) seems as good as anything else. BTW the other idea we discussed at PGCon was that we could have a postmaster option that would parse the config file and then report the amount of shared memory needed to run with it. If we had that, then it's easy to write a platform-specific shell script or program that verifies that the given number is within the allowed limits. -- Álvaro Herrera <alvhe...@commandprompt.com> The PostgreSQL Company - Command Prompt, Inc. PostgreSQL Replication, Consulting, Custom Development, 24x7 support -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
