I don't know if I missed something, but the Postgres docs seem to indicate that there is no equivalent to the concept of a SYSTEM option that exists in Drill, which can be set with a query. Options can be set at server startup, either in a configuration file or with a command line parameter [2]. Once the server is running, it appears that the closest to our ALTER SYSTEM statement would be the feature to set options at a user or database level [2].
Here is an excerpt from the docs on the DEFAULT option value: [1] - DEFAULT can be written to specify resetting the parameter to its default value (that is, whatever value it would have had if no SET had been executed in the current session). We should probably just try it out to confirm, but this statement leads me to believe that the option will return to the value set in the startup config file/parameter or what was set at the user/database level, not the system default. This is in agreement with my intuition on the issue, the whole idea behind nesting these configurations, from Drill default to System and then to Session would seem to be trying to provide users with the safest environment possible. Setting something at the system level should only be done if the administrator is certain that the non-standard option is a helpful modification for the majority of their users. Thus users can choose to override it, but their escape hatch should bring them back to the option values given by their administrator, not Drill defaults. [1] http://www.postgresql.org/docs/9.2/static/sql-set.html [2] http://www.postgresql.org/docs/9.2/static/config-setting.html On Mon, Aug 10, 2015 at 2:25 PM, Sudheesh Katkam <[email protected]> wrote: > Correction: currently any user can SET or RESET an option for session and > system. > > > On Aug 10, 2015, at 2:20 PM, Sudheesh Katkam <[email protected]> > wrote: > > > > Hey y‘all, > > > > Re DRILL-1065 <https://issues.apache.org/jira/browse/DRILL-1065>, at > system level (ALTER system RESET …), resetting an option would mean > changing the value to the default provided by Drill. But, at session level > (ALTER session RESET …), would resetting an option mean: > > (a) changing the value to the default provided by Drill? or, > > (b) changing the value to the system value, that an admin could’ve > changed? > > > > (b) would not allow non-admin users to know what the default is > (easily). However, for a given option, (a) would allow a non-admin user to > know what the default is (by resetting) and what the system setting is > (from sys.options). Opinions? > > > > Thank you, > > Sudheesh > >
