Marco Colombo wrote:
Well, many defaults are hardcoded into a file now. I'd like to see 'auto' among possible values of parameters, e.g.: with PG wild guessing reasonable values based on system specs. It may be a awful piece of code (getting system info is very platform specific), and sometimes the guess may be wrong.
The problem here is that the amount of shared memory a system can allocate is hard to discover any other way than starting the server and seeing if it works. So doing what you advise will leave the database unable to start on any system that hasn't gotten the right OS kernel tweaks done first. If there was an obvious 'auto' setting, I guarantee you newcomers would use it without consulting the documentation first, then tell everyone it doesn't work because their server broke when it was enabled. There is a technique used when you run initdb to try and detect the shared memory allocation range possible, but it really doesn't scale very well into the sizes needed to be useful for this.
-- Greg Smith 2ndQuadrant US Baltimore, MD PostgreSQL Training, Services and Support greg@xxxxxxxxxxxxxxx www.2ndQuadrant.us -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
