Re: Support for N synchronous standby servers - take 2

On 07/06/2015 09:56 PM, Michael Paquier wrote:
> On Tue, Jul 7, 2015 at 12:51 PM, Josh Berkus <josh(at)agliodbs(dot)com> wrote:
>> On 07/06/2015 06:40 PM, Michael Paquier wrote:
>>> On Tue, Jul 7, 2015 at 2:56 AM, Josh Berkus <josh(at)agliodbs(dot)com> wrote:
>>>> pro-JSON:
>>>>
>>>> * standard syntax which is recognizable to sysadmins and devops.
>>>> * can use JSON/JSONB functions with ALTER SYSTEM SET to easily make
>>>> additions/deletions from the synch rep config.
>>>> * can add group labels (see below)
>>>
>>> If we go this way, I think that managing a JSON blob with a GUC
>>> parameter is crazy, this is way longer in character size than a simple
>>> formula because of the key names. Hence, this JSON blob should be in a
>>> separate place than postgresql.conf not within the catalog tables,
>>> manageable using an SQL interface, and reloaded in backends using
>>> SIGHUP.
>>
>> I'm not following this at all. What are you saying here?
>
> A JSON string is longer in terms of number of characters than a
> formula because it contains key names, and those key names are usually
> repeated several times, making it harder to read in a configuration
> file. So what I am saying that that we do not save it as a GUC, but as
> a separate metadata that can be accessed with a set of SQL functions
> to manipulate it.

Where, though? Someone already pointed out the issues with storing it
in a system catalog, and adding an additional .conf file with a
different format is too horrible to contemplate.

--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com