Re: Sudden FTS-related error from parallel worker in 9.6

On Tue, Oct 4, 2016 at 6:33 AM, David Rowley <david.rowley@2ndquadrant.com>
wrote:
>
> The reason that you receive this message is that the main process must
> serialise all GUC settings into text before passing to the worker
> processes, and when the worker receive those serialised settings from
> the master, it must apply them so that workers behave the same way as
> the main process.
>

Thanks for the explanation. I understand that it's side-effect, but
nevertheless it's a bug leading to inability to use parallelization and it
can break some applications.


>
> Probably the question here is why is the worker process validating the
> GUC when it was not validated when postgresql.conf is loaded
>

Yes, the question is why the behavior is different. I also noticed that if
I set default_text_search_config in postgresql.conf, I don't get warning
when starting psql:

postgres@dev:~$ psql test
Timing is on.
psql (9.6.0)
Type "help" for help.


But again, if I alter database test, setting the same option, I get the
warning:

postgres@dev:~$ psql test
WARNING:  invalid value for parameter "default_text_search_config": "ru"
Timing is on.
psql (9.6.0)
Type "help" for help.