Re: pg_start_backup() takes too long

Simon Riggs wrote:
> > If it is a bug then I'd vote for just making it do an immediate
> > checkpoint --- that might cause big I/O load but it's hardly likely to
> > be worse than what will happen when you start taking the subsequent
> > filesystem backup.
>
> It was a clear intention for it to *not* cause a spike if we could avoid
> it. The idea was if you wanted it to happen quickly then you could do a
> checkpoint command first... oh well.
>
> People might want to I/O limit the backup also, which they can do
> without needing to let us know.
>
> I'm happy to put an option in for this, so we have another function:
> pg_start_backup(label text, immediate_chkpt boolean). I'll not be
> rushing to do this though given my current TODO.

I agree with Tom; either we make the pg_start_backup() checkpoint
immediate or leave the behavior unchanged.

Personally I think immediate makes more sense because issuing
pg_start_backup() seems like it should behave like a manual CHECKPOINT
command.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ If your life is a hard drive, Christ can be your backup. +