Re: Postgresql and multithreading - Mailing list pgsql-hackers

Bruce Momjian wrote:
> Let me add one more thing on this "thread".  This is one email in a long
> list of "Oh, gee, you aren't using that wizz-bang new
> sync/thread/aio/raid/raw feature" discussion where someone shows up and
> wants to know why.  Does anyone know how to address these, efficiently?

You've brought up good points here. I'm sure that you consider me guilty of
this with regard to my aio discussions. So I might offer a few specific
suggestions.

1) Someone's taking the time to generate a summary of the current thinking
with regard to a particular "whiz-bang" feature. - I can do this as a first
pass  for aio, if you think it's a good idea.

2) Including the pros and cons of the feature/implementation and how close
the group is to deciding whether something would be worth doing. - I can
also do this.

3) A set of criteria that would need to be met or demonstrated before a
feature would be considered good enough for inclusion into the main code.

If there was a separate section of the document "Developer's FAQ" that
handled this, this would help.

4) A development/feature philosophy section. Maybe three or four paragraphs
with one specific example: perhaps multi-threading.

5) I'd also suggest changing some specfics in the FAQ Section 1.2 where
there is currently:

* The usual process for source additions is:
*
* Review the TODO list.
* Discuss hackers the desirability of the fix/feature.
* How should it behave in complex circumstances?

Add here that a check should be made to the new section in the FAQ
described above. Also, section 1.1 has:

* Discussion on the patch typically happens here. If the patch adds a
* major feature, it would be a good idea to talk about it first on
* the HACKERS list, in order to increase the chances of it being
* accepted, as well as toavoid duplication of effort.

We should perhaps add here a section describing the phenomenon you describe
regarding "whiz-bang" features.

I tried to prepare as best I could before bringing anything forward to
HACKERS. In particular, I read the last two years of archives with anything
to do with the WAL log and looked at the current code, read the TODOs, read
a fair amount of discussions about aio. etc. So I was attempting to comply
with my interpretation of the process. Yet, despite these efforts, you no
doubt consider me guilty of creating unnecessary work, an outcome neither
of us desired.

I'm undeterred in my desire to come up with something meaningful and am
working on some interesting tests. I do, however, now know that the level
of scepticism and the standards of architectural purity are high. I
consider this good all around.

- Curtis