Re: Sync Rep: First Thoughts on Code

Hi,

On Wed, Dec 24, 2008 at 7:58 PM, Fujii Masao <masao(dot)fujii(at)gmail(dot)com> wrote:
> Hi,
>
> On Wed, Dec 24, 2008 at 6:57 PM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
>> Yes, OK. So I think it would only work when full_page_writes = on, and
>> has been on since last checkpoint. So two changes:
>>
>> * We just need a boolean that starts at true every checkpoint and gets
>> set to false anytime someone resets full_page_writes or archive_command.
>> If the flag is set && full_page_writes = on then we skip the checkpoint
>> entirely and use the value from the last checkpoint.
>
> Sounds good.

I attached the self-contained patch to skip checkpoint at pg_start_backup.

>
> pg_start_backup on the standby (probably you are planning?) also needs
> this logic? If so, resetting full_page_writes or archive_command should
> generate its xlog.

Now, the patch doesn't care about this.

>
> I have another thought: should we forbid the reset of archive_command
> during online backup? Currently we can do. If we don't need to do so,
> we also don't need to track the reset of archiving for fast pg_start_backup.

Now, doesn't care too.

Happy Holidays!

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