Re: Stating the significance of Lehman & Yao in the nbtree README

From: Peter Geoghegan <pg(at)heroku(dot)com>
To: Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
Cc: Pg Hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: Stating the significance of Lehman & Yao in the nbtree README
Date: 2014-07-24 03:58:25
Message-ID: CAM3SWZRMH6=tbovZMf7mzj7F5TzEhp27A-xyoBo6Gj9O+WFJSg@mail.gmail.com
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On Wed, Jul 23, 2014 at 8:52 PM, Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> As such there is no problem in saying the way you have mentioned, but
> I feel it would be better if we can mention the mechanism of _bt_search()
> as quoted by you upthread in the first line.
> "> In more concrete terms, _bt_search() releases and only then acquires
>> read locks during a descent of the tree (by calling
>> _bt_relandgetbuf()), and, perhaps counterintuitively, that's just
>> fine."

I guess I could say that too.

> One more point, why you think it is important to add this new text
> on top? I think adding new text after "Lehman and Yao don't require read
> locks, .." paragraph is okay.

I've added it to the top because it's really the most important point
on Lehman and Yao. It's the _whole_ point. Consider how it's
introduced here, for example:
http://db.cs.berkeley.edu/jmh/cs262b/treeCCR.html

Why should I "bury the lead"?

--
Peter Geoghegan

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