Re: Proposal for changes to recovery.conf API

David Steele <david@pgmasters.net>

From: David Steele <david@pgmasters.net>
To: pgsql-hackers@postgresql.org
Date: 2016-09-06T11:52:45Z
Lists: pgsql-hackers
On 9/6/16 4:56 AM, Petr Jelinek wrote:
> On 06/09/16 07:18, Abhijit Menon-Sen wrote:
>>
>> Do we want something like this (easy to implement and document, perhaps
>> not especially convenient to use):
>>
>>     recovery_target = 'xid'     # or 'time'/'name'/'lsn'/'immediate'
>>     recovery_target_xid = xxx?  # the only setting we care about now
>>     recovery_target_otherthings = parsed_but_ignored
>>
>> Or something like this (a bit harder to implement):
>>
>>     recovery_target = 'xid:xxx' # or 'time:xxx' etc.
>>
>
> Personally, I never liked the fact that we have several config variables
> for this and then the last one is chosen (even when it was in
> recovery.conf). We support one recovery_target at a time so it would
> make sense to have single config option for it IMHO.
>
> So +1 on the recovery_target = 'xid:xxx' idea.

I would rather not combine the type and target into a single field - how 
about having two fields:

recovery_target_type = 'xid|time|name|immediate'
recovery_target = 'value'

recovery_target would be ignored when recovery_target_type = 'immediate'.

-- 
-David
david@pgmasters.net