Re: Formatting Curmudgeons WAS: MMAP Buffers

On Sat, Apr 16, 2011 at 11:26:34PM -0500, Kevin Grittner wrote:
> I have to say, I've been rather mystified by the difficulty
> attributed to running pgindent. During work on the SSI patch, I ran
> it about once every two weeks on files involved in the patch

Well, as a counterpoint: during work on the SSI patch, I did *not* run
pgindent. I attempted to, at one point, but was discouraged when I
realized that it required BSD indent and my Linux machine only had GNU
indent. That meant I would need to find, build, and install a new
version of indent, and keep it separate from my existing GNU indent.
Hardly impossible, but it's a lot more of a hassle than simply running a
script, and it left me wondering if I was going to run into other
issues even if I did get the right indent installed.

Andrew's instructions upthread would certainly have been helpful to
have in the pgindent README.

(To be fair, I would probably have made much more of an effort to run
pgindent if I didn't already know Kevin was running it periodically on
the SSI code.)

> And I can't help but wonder why, in an off-list discussion with
> Michael Cahill about the SSI technology he commented that he was
> originally intending to implement the technique in PostgreSQL, but
> later chose Oracle Berkeley DB and then latter InnoDB instead.
> *Maybe* he was looking toward being hired by Oracle, and *maybe* it
> was because the other databases already had predicate locking and
> true serializable transaction isolation levels -- but was part of it
> the reputation of the community? I keep wondering.

I would discount the first explanation (being hired at Oracle)
entirely. I think the second explanation is the correct one: it's
simply much more difficult to implement SSI atop a database that does
not already have predicate locking (as we know!)

But I am aware of other cases in which people in the academic community
have done work that could well be of interest to the Postgres community
but didn't submit their work here. In part, that was because they did
not have the time/motivation to get the work into a polished,
acceptable state, and in part because of the reputation of the
community.

Dan

--
Dan R. K. Ports MIT CSAIL http://drkp.net/