Re: max_standby_delay considered harmful

Simon Riggs wrote:
> On Thu, 2010-05-06 at 16:09 +0200, Dimitri Fontaine wrote:
>> Simon Riggs <simon(at)2ndQuadrant(dot)com> writes:
>>> It would be easier to implement a conflict resolution plugin that is
>>> called when a conflict occurs, allowing users to have a customisable
>>> mechanism. Again, I have no objection to that proposal.
>> To implement, if you say so, no doubt. To use, that means you need to
>> install a contrib module after validation that the trade offs there are
>> the one you're interested into, or you have to code it yourself. In C.
>>
>> I don't see that as an improvement over what we have now. Our main
>> problem seems to be the documentation of the max_standby_delay, where we
>> give the impression it's doing things the code can not do. IIUC.
>
> I meant "easier to implement than what Florian suggested".
>
> The plugin would also allow you to have the pause/resume capability.

Not the same plugin. A hook for stop/resume would need to be called
before and/or after each record, the one for conflict resolution would
need to be called at each conflict. Designing a good interface for a
plugin is hard, you need at least a couple of samples ideas for plugins
that would use the hook, before you know the interface is flexible enough.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com