Horton

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Commits

  1. doc: Move wal_init_zero and wal_recycle descriptions to proper section.

  1. wal_init_zero and wal_recycle

    Fujii Masao <masao.fujii@oss.nttdata.com> — 2020-05-27T03:27:26Z

    Hi,

The group of wal_init_zero and wal_recycle is WAL_SETTINGS in guc.c,
but their descriptions are located in "19.6. Replication"/"19.6.1. Sending
Servers" section. This seems a documentation bug. They should be located
in "19.5. Write Ahead Log"/"19.5.1. Settings". Thought?

Regards,

-- 
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION

  2. Re: wal_init_zero and wal_recycle

    Simon Riggs <simon@2ndquadrant.com> — 2020-05-27T07:08:48Z

    On Wed, 27 May 2020 at 04:27, Fujii Masao <masao.fujii@oss.nttdata.com>
wrote:

> Hi,
>
> The group of wal_init_zero and wal_recycle is WAL_SETTINGS in guc.c,
> but their descriptions are located in "19.6. Replication"/"19.6.1. Sending
> Servers" section. This seems a documentation bug. They should be located
> in "19.5. Write Ahead Log"/"19.5.1. Settings". Thought?
>

+1

Why are there two settings for the same thing (COW support)?
Would we really want to allow setting one but not the other?

-- 
Simon Riggs                http://www.2ndQuadrant.com/
<http://www.2ndquadrant.com/>
Mission Critical Databases

  3. Re: wal_init_zero and wal_recycle

    Thomas Munro <thomas.munro@gmail.com> — 2020-05-27T23:43:45Z

    On Wed, May 27, 2020 at 7:09 PM Simon Riggs <simon@2ndquadrant.com> wrote:
> On Wed, 27 May 2020 at 04:27, Fujii Masao <masao.fujii@oss.nttdata.com> wrote:
>>
>> Hi,
>>
>> The group of wal_init_zero and wal_recycle is WAL_SETTINGS in guc.c,
>> but their descriptions are located in "19.6. Replication"/"19.6.1. Sending
>> Servers" section. This seems a documentation bug. They should be located
>> in "19.5. Write Ahead Log"/"19.5.1. Settings". Thought?
>
>
> +1
>
> Why are there two settings for the same thing (COW support)?
> Would we really want to allow setting one but not the other?

In the long discussion[1] we decided to invent GUCs that tell you
precisely what they do, rather than trying to have a mysterious "COW
filesystem mode", given the apparent lack of COW filesystem expertise
in the thread (for example: claims, theories and data about ZFS were
presented, but do they also apply to BTRFS, APFS, ReFS, ...?  I dunno,
and no one showed up with more information on that.)

[1] https://www.postgresql.org/message-id/flat/CACPQ5Fo00QR7LNAcd1ZjgoBi4y97%2BK760YABs0vQHH5dLdkkMA%40mail.gmail.com

  4. Re: wal_init_zero and wal_recycle

    Fujii Masao <masao.fujii@oss.nttdata.com> — 2020-05-29T04:13:34Z

    
On 2020/05/28 8:43, Thomas Munro wrote:
> On Wed, May 27, 2020 at 7:09 PM Simon Riggs <simon@2ndquadrant.com> wrote:
>> On Wed, 27 May 2020 at 04:27, Fujii Masao <masao.fujii@oss.nttdata.com> wrote:
>>>
>>> Hi,
>>>
>>> The group of wal_init_zero and wal_recycle is WAL_SETTINGS in guc.c,
>>> but their descriptions are located in "19.6. Replication"/"19.6.1. Sending
>>> Servers" section. This seems a documentation bug. They should be located
>>> in "19.5. Write Ahead Log"/"19.5.1. Settings". Thought?
>>
>>
>> +1

Thanks! Patch attached.
Since they are located just before wal_buffers in postgresql.conf.sample,
I moved the descriptions of them also just before that of wal_buffers
in "Write Ahead Log"/"Settings" section.

BTW, while reading guc.c, I found the GUC context of wal_recycle is
PGC_SUSET. But isn't it better to set it to PGC_SIGHUP because wal_recycle
doesn't affect any backends? Basically checkpointer and startup process
use wal_recycle.

Regards,

-- 
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION

  5. Re: wal_init_zero and wal_recycle

    Fujii Masao <masao.fujii@oss.nttdata.com> — 2020-06-02T05:25:02Z

    
On 2020/05/29 13:13, Fujii Masao wrote:
> 
> 
> On 2020/05/28 8:43, Thomas Munro wrote:
>> On Wed, May 27, 2020 at 7:09 PM Simon Riggs <simon@2ndquadrant.com> wrote:
>>> On Wed, 27 May 2020 at 04:27, Fujii Masao <masao.fujii@oss.nttdata.com> wrote:
>>>>
>>>> Hi,
>>>>
>>>> The group of wal_init_zero and wal_recycle is WAL_SETTINGS in guc.c,
>>>> but their descriptions are located in "19.6. Replication"/"19.6.1. Sending
>>>> Servers" section. This seems a documentation bug. They should be located
>>>> in "19.5. Write Ahead Log"/"19.5.1. Settings". Thought?
>>>
>>>
>>> +1
> 
> Thanks! Patch attached.
> Since they are located just before wal_buffers in postgresql.conf.sample,
> I moved the descriptions of them also just before that of wal_buffers
> in "Write Ahead Log"/"Settings" section.

Barring any objection, I will commit this patch.

Regards,

-- 
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION

  6. Re: wal_init_zero and wal_recycle

    Fujii Masao <masao.fujii@oss.nttdata.com> — 2020-06-03T01:16:55Z

    
On 2020/06/02 14:25, Fujii Masao wrote:
> 
> 
> On 2020/05/29 13:13, Fujii Masao wrote:
>>
>>
>> On 2020/05/28 8:43, Thomas Munro wrote:
>>> On Wed, May 27, 2020 at 7:09 PM Simon Riggs <simon@2ndquadrant.com> wrote:
>>>> On Wed, 27 May 2020 at 04:27, Fujii Masao <masao.fujii@oss.nttdata.com> wrote:
>>>>>
>>>>> Hi,
>>>>>
>>>>> The group of wal_init_zero and wal_recycle is WAL_SETTINGS in guc.c,
>>>>> but their descriptions are located in "19.6. Replication"/"19.6.1. Sending
>>>>> Servers" section. This seems a documentation bug. They should be located
>>>>> in "19.5. Write Ahead Log"/"19.5.1. Settings". Thought?
>>>>
>>>>
>>>> +1
>>
>> Thanks! Patch attached.
>> Since they are located just before wal_buffers in postgresql.conf.sample,
>> I moved the descriptions of them also just before that of wal_buffers
>> in "Write Ahead Log"/"Settings" section.
> 
> Barring any objection, I will commit this patch.

Pushed. Thanks!

Regards,

-- 
Fujii Masao
Advanced Computing Technology Center
Research and Development Headquarters
NTT DATA CORPORATION