Re: Detach/attach database

On 13 November 2011 15:26, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
> On Sun, Nov 13, 2011 at 1:13 PM, Thom Brown <thom(at)linux(dot)com> wrote:
>
>> I don't know if this has been discussed before, but would it be
>> feasible to introduce the ability to detach and attach databases? (if
>> you're thinking "stop right there" skip to the end)  What I had in
>> mind would be to do something like the following:
>
> That would be better done at the tablespace level, and then the
> feature becomes "transportable tablespaces". Which seems like a good
> and useful idea to me.

I've been trying to think why the tablespace equivalent would be
better but can't see it. The reason for detaching a database would be
that you want do so something with an entire related set of data. A
tablespace can contain just indexes, or a few tables from several
databases.

>> You may now be able to infer where this notion came from, when someone
>> asked if you can clone databases without kicking users off.  However,
>> this isn't a schema-only copy, but naturally contains data as well.
>
> The OP wanted to do this without freezing activity on the database,
> which is not easy...
>
> OTOH we can do a backup of just a single database and then filter
> recovery at database level to produce just a single copy of another
> database on its own server, if anyone wanted that.

Filtering recovery sounds very tricky to me. And it's the global
objects part which makes things extra difficult. But the whole idea I
was seeking sounds riddled with holes anyway, but glad I can at least
put it from my mind.

So can I humbly request we completely re-architect the whole of
PostgreSQL to fit this feature? Thanks.

--
Thom Brown
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