Re: Proof of concept: standalone backend with full FE/BE protocol

On Tue, Nov 13, 2012 at 12:38 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Simon Riggs <simon(at)2ndquadrant(dot)com> writes:
>> The most popular relational database in the world is Microsoft Access,
>> not MySQL. Access appears desirable because it allows a single user to
>> create and use a database (which is very good). But all business
>> databases have a requirement for at least one of: high availability,
>> multi-user access or downstream processing in other parts of the
>> business.
>
> That's a mighty sweeping claim, which you haven't offered adequate
> evidence for. The fact of the matter is that there is *lots* of demand
> for simple single-user databases, and what I'm proposing is at least a
> first step towards getting there.
>
> The main disadvantage of approaching this via the existing single-user
> mode is that you won't have any autovacuum, bgwriter, etc, support.
> But the flip side is that that lack of infrastructure is a positive
> advantage for certain admittedly narrow use-cases, such as disaster
> recovery and pg_upgrade. So while I agree that this isn't the only
> form of single-user mode that we'd like to support, I think it is *a*
> form we'd like to support, and I don't see why you appear to be against
> having it at all.
>
> A more reasonable objection would be that we need to make sure that this
> isn't foreclosing the option of having a multi-process environment with
> a single user connection. I don't see that it is, but it might be wise
> to sketch exactly how that case would work before accepting this.

I'm not particularly excited about providing more single-user mode
options, but I think it's worth having this particular thing because
it makes pg_upgrade more robust. Whether we do anything else is
something we can litigate when the time comes.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company