Re: Fix to expose a GUC variable, Log_disconnections, to outside of postgres.c

On 07/09/2015 07:19 AM, Satoshi Nagayasu wrote:
> 
> On 2015/07/09 13:06, Tom Lane wrote:
>> Satoshi Nagayasu <snaga@uptime.jp> writes:
>>> I just found that Log_disconnections value has not been
>>> exposed to outside of postgres.c.
>>> Despite that, Log_connections has already been exposed.
>>
>> Why would an external module need to touch either one?
> 
> To check settings of GUC variables from a shared preload
> library.
> 
> For example, I'd like to print "WARNING ...." in _PG_init()
> when some GUC variable is disabled on postmaster startup.

I still have a hard time seeing why an extension would be interested in
Log_disconnections. But hey, extensions do strange things..

You could use GetConfigOption(). I'm not necessarily opposed to exposing
Log_disconnections, but with GetConfigOption() it will work with earlier
versions too.

- Heikki