Re: Core team statement on replication in PostgreSQL

Tom Lane wrote:
> Simon Riggs <simon@2ndquadrant.com> writes:
>   
>> On Fri, 2008-05-30 at 12:31 +0530, Gurjeet Singh wrote:
>>     
>>> On Fri, May 30, 2008 at 10:40 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>>       
>>>> But since you mention it: one of the plausible answers for fixing the
>>>> vacuum problem for read-only slaves is to have the slaves push an xmin
>>>> back upstream to the master to prevent premature vacuuming.
>>>>         
>>> I think it would be best to not make the slave interfere with the
>>> master's operations; that's only going to increase the operational
>>> complexity of such a solution.
>>>       
>
>   
>> We ruled that out as the-only-solution a while back. It does have the
>> beauty of simplicity, so it may exist as an option or possibly the only
>> way, for 8.4.
>>     
>
> Yeah.  The point is that it's fairly clear that we could make that work.
> A solution that doesn't impact the master at all would be nicer, but
> it's not at all clear to me that one is possible, unless we abandon
> WAL-shipping as the base technology.
>
>             
>   

Quite. Before we start ruling things out let's know what we think we can 
actually do.

I hope that NTT will release their code ASAP so we will have a better 
idea of what we have and what we need.

cheers

andrew