On Fri, Jan 23, 2015 at 3:49 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > > I know what the proposal is. What I am questioning is the use-case that > justifies having us build and support all this extra mechanism. How often > does anyone need to know what the "next down" variable value would be?
I would say not that often as I think nobody changes the settings in configuration files every now and then, but it could still be meaningful in situations as described upthread by Sawada. I think similar to this, pg_reload_conf() or many such things will be used not that frequently, it seems to me that here important point to consider is that whether such a view could serve any purpose for real users? If we see multiple value for same config parameter was possible even previous to Alter System and there doesn't seem to be much need/demand for such a view and the reason could be that user has no way of changing the setting at file level with command, but now as we provide a way it could be useful in certain cases when user want to retain previous values (value in postgresql.conf). I understand that usage of such a view is not that high, but it could be meaningful in some cases. > And if they do need to know whether a variable is set in postgresql.conf, > how often wouldn't they just resort to "grep" instead? > Do always user/dba (having superuser privilege) access to postgresql.conf file? It seems to me even if they have access, getting the information via SQL would be more appealing. > (Among other > points, grep would succeed at noticing commented-out entries, which this > mechanism would not.) > GUC has existed in more or less its current state for about 15 years, > and I don't recall a lot of complaints that would be solved by this. > Furthermore, given that ALTER SYSTEM was sold to us as more or less > obsoleting manual editing of postgresql.conf, I rather doubt that it's > changed the basis of discussion all that much. > By providing such a view I don't mean to recommend the user to change the settings by editing postgresql.conf manually and then use Alter System for other cases, rather it could be used for some cases like for default values or if in rare cases user has changed the parameters manually. With Regards, Amit Kapila. EnterpriseDB: http://www.enterprisedb.com