On Fri, Aug 23, 2013 at 6:01 PM, Stephen Frost <sfr...@snowman.net> wrote: > * Amit Kapila (amit.kapil...@gmail.com) wrote: >> On Thu, Aug 22, 2013 at 6:06 PM, Stephen Frost <sfr...@snowman.net> wrote: >> > * Amit Kapila (amit.kapil...@gmail.com) wrote: >> >> Enable/Disable reading of auto file >> >> ----------------------------------------------------- >> >> a. Have a new include in postresql.conf >> >> #include_auto_conf_file postgresql.auto.conf >> >> as it is a special include, we can read this file relative to data >> >> directory. >> >> >> >> Enable/Disable Alter System command >> >> ----------------------------------------------------------- >> >> This can be achieved in 3 ways: >> >> a. Check before executing Alter System if include directive is >> >> disabled, then just issue a warning to user and proceed with command. >> >> b. Check before executing Alter System if include directive is >> >> disabled, then just issue an error and stop. >> > >> > It doesn't make sense for it to be a 'warning' with this- the >> > parameter specifies the file to use. If you don't know what file to >> > use, how you can possibly do anything but return an error? >> >> As the file and location are fixed, we can go-ahead and write to >> it, but I think now we are deciding >> if someone disables include dir, then we can just disable Alter >> System, so it is better to return error in such >> situation. > > It wouldn't be fixed with this approach. > >> > Note that I *like* that about this approach. >> > >> > There are a few other considerations with this- >> > >> > - What should the default be? (Still thinking 'off' myself) >> default 'off' is a safe option, as it won't allow users to make >> any change to parameter values until/unless they >> read from manual, how to use it and what can go wrong, on the >> other side it will be bit hassle for user to use this >> command. I think 'on' would be better. > > Yeah, no, I still think 'off' would be best for this particular option. > >> > - What happens if the user specifies 'postgresql.conf'? I'm thinking we >> > would disallow such insanity (as that's what it is, imv..) by having >> > an identifier in the file that this is the PG "auto conf" file. >> I think we can detect by name and give error. >> > - Should we have such an identifier in auto.conf to indicate that we >> > created it, to prevent the user from setting it to something they >> > shouldn't? >> I think if user plays with this file manually, it can lead to >> problems, that's why earlier we have >> decided to keep a note on top of file which will indicate, do not >> edit this file manually. >> I believe that should be sufficient. > > I agree that having such a disclaimer at the top of the file is a good > idea. I'm not completely convinced that's sufficient but it's certainly > better than nothing. > >> > - What's the "bootstrap" mode; iow, if a user enables the option but the >> > file doesn't exist, what do we do? With this approach, I'd be >> > inclined to say we simply create it and put the marker to indicate >> > it's "our" file. >> >> Alter System will create the file if doesn't exist. > > ... Only if it's enabled though.
Yes. > >> > - Should we allow it to be outside of the data dir? We could simply log >> > an error and ignore the parameter if it's more than a simple filename. >> >> This should be an error, the file location and name will be fixed. > > Not with this proposal... If it's fixed then it makes no sense to make it > look like it can be modified. This proposal is to have a special include which user can only use for enable/disable which means he can remove symbol '#' or add '#'. We cannot stop user from changing file name or add some different location, but that can lead to problems. We can have a note on top of this include indicating it is only for enable/disable. I think if we add more meaning to it, like allow user to change it, handling and defining of that will be bit complex. With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers