Re: Acclerating INSERT/UPDATE using UPS

Hideyuki Kawashima wrote:
> Joshua,
>
> I appreciate your great suggestion!
> It is great honor for me if Sigres will be merged to PostgreSQL.
> Since the changes of Sigres from PostgreSQL-8.2.1 are not many,
> and moreover, all of changes are surrounded with #ifdef SIGRES --- #endif,
> incorporating Sigres into PostgreSQL would be easy.

The best way is to create a patch against -head and submit that patch
with a complete description of why, and what. If you have test cases
that show the improvement all the better.

I would suggest though if you are going to submit the patch that you
take a look at how you could disable/enable the feature within the
postgresql.conf via a guc.

Sincerely,

Joshua D. Drake

>
> However, Sigres modifies WAL which is the most important point of DBMS
> on stability.
> Although I myself could not find any bugs in Sigres, I am really afraid
> of it. It a bug exists on Sigres, it puts everyone to huge
> inconvenience... Therefore, before incorporating Sigres into PostgreSQL,
> the code must be checked, and the behaviors of Sigres must be checked
> carefully. Since PostgreSQL is a famous and wide spread software, I
> strongly want to avoid losing its great reputation. Unfortunately in
> Japan, I do not know any WAL hackers except for a friend of mine, and he
> is too busy to check Sigres. So, if pgsql-hackers checks Sigres, I am
> really happy.
>
> Best Regards,
>
> -- Hideyuki
>
> Joshua D. Drake wrote:
>> Hideyuki Kawashima wrote:
>>
>>> Joshua,
>>>
>> :)
>>
>>
>>> The reason why I made the Sigres is, the advances of recent non volatile
>>> memories. Just now we do not usually use non volatile memories. But in
>>> the near future, situation would change. I think if a non volatile
>>> memories can be considered as a persistence device, PostgreSQL WAL
>>> mechanism should be modified.
>>> However, I do not use such devices usually. Thus I made Sigres which
>>> requires UPS.
>>>
>> This is actually very interesting. We (www.commandprompt.com) have had
>> several customers ask us how we can make PostgreSQL more reasonable
>> within a flash environment.
>>
>> I agree with you that in the future you will see many such databases
>> including PostgreSQL living on these devices.
>>
>> Tom? What do you think? Is there some room for movement here within the
>> postgresql.conf to make something like sigres usable within PostgreSQL
>> proper?
>>
>>
>>> Currently I have just ignored XLogWrite and WALWriteLock, but a friend
>>> of mine (a Japanese great hacker of PostgreSQL) has more idea to improve
>>> WAL if a battery supplied memory can be considered as a persistent device.
>>>
>>>
>> We are coming up very quickly on a feature freeze for the next version
>> of PostgreSQL. If... we can has something out quickly enough and in a
>> thought out fashion, the hackers may be willing to accept a patch for
>> 8.3.. If not there is always 8.4..
>>
>> Sincerely,
>>
>> Joshua D. Drake
>>
>>
>>
>>
>>
>

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