Re: WAL format and API changes (9.5)

On Mon, Oct 6, 2014 at 8:19 PM, Heikki Linnakangas <hlinnakangas(at)vmware(dot)com>
wrote:

> On 10/06/2014 04:42 AM, Michael Paquier wrote:
>
>> On Fri, Oct 3, 2014 at 9:51 PM, Heikki Linnakangas <
>> hlinnakangas(at)vmware(dot)com>
>> wrote:
>>
>>> So I now have a refactoring patch ready that I'd like to commit (the
>>>
>> attached two patches together), but to be honest, I have no idea why the
>> second patch is so essential to performance.
>> Thanks. I did some more tests with master, master+patch1,
>> master+patch1+CRC
>> refactoring, but I am not able to see any performance difference with
>> pgbench (--no-vacuum, -t) and the test suite you provided, just some noise
>> that barely changed performance.
>>
>
> Thanks for the confirmation. I'm really going crazy with benchmarking
> this. Sometimes I see a big difference, the next day it's gone.
>
The benchmark paradigms.

> * Fixed XLogSaveBufferForHint. It didn't initialize BkpBlock struct,
> rendering it completely broken.
>
Note for other reviewers: that's represented by this addition in
XLogSaveBufferForHint:
+ /* Make a BkpBlock struct representing the buffer */
+ XLogFillBkpBlock(buffer, buffer_std, &bkpb)

Regards,
--
Michael