Re: Support for N synchronous standby servers - take 2

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.
--
Michael