Re: odd pg_start_backup() issue

On Fri, Jan 31, 2014 at 9:55 AM, CS DBA <cs_dba@consistentstate.com> wrote:
[...]
> Next I'll try this (I assume the first checkpoint is simply un-needed):
> echo "select pg_start_backup('$tag'); checkpoint;" | psql
> However, this  works well and the pg_start_backup finishes in less than
> 1minute,

I wonder how it helped at all, because it should not. Probably it was
some kind of a coincidence.

[...]
> Thoughts?

The note below is from the docs for pg_start_backup().

"pg_start_backup(label text [, fast boolean ])
...
There is an optional second parameter of type boolean. If true, it
specifies executing pg_start_backup as quickly as possible. This
forces an immediate checkpoint which will cause a spike in I/O
operations, slowing any concurrently executing queries."

So all you need is to specify 'true' as a second parameter.

select pg_start_backup('$tag', true)

--
Kind regards,
Sergey Konoplev
PostgreSQL Consultant and DBA

http://www.linkedin.com/in/grayhemp
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