Horton

Re: Online base backup from the hot-standby

Fujii Masao <masao.fujii@gmail.com>

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From: Fujii Masao <masao.fujii@gmail.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Jun Ishiduka <ishizuka.jun@po.ntts.co.jp>, ssinger_pg@sympatico.ca, cedric.villemain.debian@gmail.com, pgsql-hackers@postgresql.org
Date: 2011-08-18T01:43:21Z
Lists: pgsql-hackers 
On Thu, Aug 18, 2011 at 12:09 AM, Robert Haas <robertmhaas@gmail.com> wrote:
> Ugh, you're right.  But then you might have problems if the state
> changes again before all backends have picked up the previous change.

Right.

> What I've thought about before is making one backend (say, bgwriter)
> store its latest value in shared memory, protected by some lock that
> would already be held at the time the value is needed.  Everyone else
> uses the shared memory copy instead of relying on their local value.

Sounds reasonable.

Regards,

-- 
Fujii Masao
NIPPON TELEGRAPH AND TELEPHONE CORPORATION
NTT Open Source Software Center