Re: Will switchover still need a checkpoint in 9.1 SR Hot Standby - Mailing list pgsql-hackers

From PostgreSQL - Hans-Jürgen Schönig
Subject Re: Will switchover still need a checkpoint in 9.1 SR Hot Standby
Date
Msg-id 8E2746BE-5F0C-4CFC-8D18-6C59CC5A74D2@cybertec.at
Whole thread Raw
In response to Re: Will switchover still need a checkpoint in 9.1 SR Hot Standby  (Simon Riggs <simon@2ndQuadrant.com>)
List pgsql-hackers
On Aug 7, 2011, at 11:01 AM, Simon Riggs wrote:

> On Sun, Aug 7, 2011 at 8:57 AM, Hannu Krosing <hannu@2ndquadrant.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


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