Re: Will switchover still need a checkpoint in 9.1 SR Hot Standby

On Aug 7, 2011, at 11:01 AM, Simon Riggs wrote:

> On Sun, Aug 7, 2011 at 8:57 AM, Hannu Krosing <hannu(at)2ndquadrant(dot)com> wrote:
>> In 9.0 (as in earlier versions) a former standby host has to do a full
>> checkpoint before becoming available as an independent database instance
>> in either switchover or failover scenarios.
>>
>> For most combinations of of bigger than minimal shared buffers and
>> non-memory-speed disks this can take from several seconds to tens of
>> minutes on busy systems.
>
> For switchover, you issue a checkpoint first, to reduce this time as
> much as possible.
>
>> Is the pre-activation checkpoint still required in 9.1 ?
>
> Yes, but I've found a way to remove them in 9.2 and will be patching that soon.

hi simon,

this is highly interesting. this is am important issue for big iron.
can you share the idea you have in mind?

many thanks,

hans

--
Cybertec Schönig & Schönig GmbH
Gröhrmühlgasse 26
A-2700 Wiener Neustadt, Austria
Web: http://www.postgresql-support.de