Re: Streaming a base backup from master

Heikki Linnakangas <heikki(dot)linnakangas(at)enterprisedb(dot)com> writes:
> On 03/09/10 15:16, Greg Stark wrote:
>> On Fri, Sep 3, 2010 at 12:19 PM, Heikki Linnakangas
>> <heikki(dot)linnakangas(at)enterprisedb(dot)com> wrote:
>>> * We need a smarter way to do pg_start/stop_backup() with this. At the
>>> moment, you can only have one backup running at a time, but we shouldn't
>>> have that limitation with this built-in mechanism.
>>
>> Well there's no particular reason we couldn't support having multiple
>> pg_start_backup() pending either. It's just not usually something
>> people have need so far.

> The backup label file makes that hard. There can be only one at a time.

I don't actually see a use-case for streaming multiple concurrent
backups. How many people are going to be able to afford that kind of
load on the master's I/O bandwidth?

Certainly for version 1, it would be sufficient to throw an error if
someone tries to start a backup while another one is in progress.
*Maybe*, down the road, we'd want to relax it.

regards, tom lane